The top two clubs in five of the six Heineken Cup pools will go head-to-head in the key round 3 and 4 pre-Christmas back-to-back fixtures, which traditionally go a long way to deciding the qualifiers for the tournament knockout stages.
Of the seven unbeaten clubs after the opening two rounds of the 2012/13 season, two find themselves ready to do battle in Pool 5, and reigning champions Leinster Rugby and ASM Clermont Auvergne have a long-standing Heineken Cup rivalry.
They met in last season's memorable semi-final at Stade Chaban Delmas in Bordeaux when Leinster dramatically edged the verdict 19-15, then clashed in the pool stages of the 2010/11 tournament in the same order as this season at Stade Marcel Michelin and the Aviva Stadium, and they were adversaries at the quarter-final stage in 2010 at the RDS in Dublin.
Although Leinster lead the series between the two clubs 5-1 dating back to 2002, Clermont are in vintage form in Europe going into Sunday's eagerly anticipated Pool 5 contest, and are the only club with a maximum 10 points in the current competition.
High-scoring Saracens, who have registered victories over Edinburgh Rugby and Racing Metro 92 to date, will be looking to maintain their lead at the top of Pool 1 when they take on two-time tournament winners, Munster Rugby, in the first of the back-to-back games at Thomond Park on Saturday.
In Pool 2, four-time champions Toulouse continue their quest for yet another Heineken Cup success when they go up against Ospreys at Stade Ernest Wallon on Saturday. The clubs met in the back-to-back rounds in the 2003/04 season with Toulouse winning both contests 26-9 and 29-11.
Ulster Rugby, who are aiming to go one better than last season when they were defeated in the final by Leinster, clash with Northampton Saints in Pool 4 at Franklin's Gardens on Friday. While the 2011 finalists, Northampton, are bound to have other ideas, Ulster will be looking to extend their unbeaten run in all competitions this season.
Current Top 14 leaders and Pool 6 toppers, Toulon, will play Sale Sharks for the first time in the Heineken Cup when the two go head-to-head at Salford City Stadium on Saturday.
Round 3 fixtures
07-Dec-12 19:35 Glasgow Warriors v Castres Olympique at Scotstoun
07-Dec-12 20:00 Connacht Rugby v Biarritz Olympique Pays Basque at The Sportsground
07-Dec-12 20:00 Northampton Saints v Ulster Rugby at Franklin's Gardens
08-Dec-12 13:35 Scarlets v Exeter Chiefs at Parc y Scarlets
08-Dec-12 14:35 Toulouse v Ospreys at Stade Ernest Wallon
08-Dec-12 14:35 Zebre v Harlequins at Stadio XXV Aprile
08-Dec-12 15:40 Sale Sharks v Toulon at Salford City Stadium
08-Dec-12 18:00 Munster v Rugby Saracens at Thomond Park
08-Dec-12 19:00 Racing Metro 92 v Edinburgh Rugby at Stade Yves du Manoir
09-Dec-12 12:45 Cardiff Blues v Montpellier at Cardiff Arms Park
09-Dec-12 15:00 Leicester Tigers v Benetton Treviso at Welford Road
09-Dec-12 16:00 ASM Clermont Auvergne v Leinster Rugby at Stade Marcel Michelin
Game by Game
Pool 4: Glasgow Warriors v Castres Olympique
Friday, 7th December 2012, Kick off: 19:35, Scotstoun Stadium
Referee: Wayne Barnes (Eng), Assistant Ref: Martin Fox (Eng), Assistant Ref: Paul Dix (Eng), TMO: N/A Citing Commissioner: Shaun Gallagher (Eng)
• Against French opposition, Glasgow have a 25% win rate. They have won six, lost 16 and drawn twice against French sides in the Heineken Cup.
• Glasgow have failed to win any of their last five Heineken Cup matches, losing four and drawing one.
• Glasgow have a goal kicking success rate of 43%, lower than any other team in the tournament this season.
• Castres have suffered defeat in nine of their last 11 Heineken Cup matches, but ended a four-match losing streak with a win over Northampton in round two of the pool stages
Pool 4: Northampton Saints v Ulster
Friday, 7th December 2012, Kick off: 20:00, Franklin's Gardens
Referee: Jerome Garces (Fra), Assistant Ref: Patrick Pechambert (Fra), Assistant Ref: Sebastien Cloute (Fra), TMO: Laurent Valin (Fra), Citing Commissioner: Jean-Claude Legendre (Fra)
• Northampton fare worse against teams from Ireland than any other nation in this tournament. They have lost 8 of 12 matches against Irish outfits.
• Northampton have conceded turnovers on 38 occasions this season, more than any other team in the Heineken Cup.
• Saints' Ken Pisi is the leading metre maker in the tournament so far, carrying the ball for
272 metres in his two appearances.
• Ulster are chasing their 50th win overall in the Heineken Cup. They have won 49 of 105 contests to date.
Pool 3: Connacht Rugby v Biarritz Olympique Pays Basque
Friday, 7th December 2012, Kick off: 20:00, The Sportsground
Referee: Greg Garner (Eng), Assistant Ref: Luke Pearce (Eng), Assistant Ref: Paul Burton (Eng), TMO: Trevor Fisher (Eng), Citing Commissioner: Douglas Hunter (Sco)
• Connacht have lost two out of two against French opponents in the Heineken Cup. In the Amlin Challenge Cup, they have 27 wins and 20 losses against teams from France.
• Biarritz have failed to string two wins together in their last eight games in the Heineken Cup, but have also not lost consecutive matches in that period. If their current trend of form continues against Connacht, they will lose this game.
• The French outfit have won eight and lost seven Heineken Cup matches against Irish sides. Six of those eight wins came in their last eight encounters against Irish outfits.
• Connacht have won 15 lineouts so far this season, a joint-low in the tournament so far.
Pool 5: Scarlets v Exeter Chiefs
Saturday, 8th December 2012, Kick off: 13:35, Parc Y Scarlets
Referee: Mathieu Raynal (Fra), Assistant Ref: Jean-Luc Rebollal (Fra), Assistant Ref: Jerome Lamirnad (Fra), TMO: Herve Dubes (Fra), Citing Commissioner: Eugene Ryan (Ire)
• Scarlets have 13 wins and 18 losses against English opposition in this tournament, a win rate of 42%.
• The Welsh side have lost five of their last six Heineken Cup matches, three of which were settled by margins of a converted try or under.
• Exeter are one of two teams yet to touch down for a try in this year's tournament, the other being scoreless Edinburgh.
• Exeter have averaged the most passes per game so far this season (179).
• Scarlets' 14 turnovers conceded so far this season is the lowest total in the tournament.
Pool 2: Toulouse v Ospreys
Saturday, 8th December 2012, Kick off: 14:35, Stade Ernest Wallon
Referee: Allain Rolland (Ire), Assistant Ref: Sean Gallagher (Ire), Assistant Ref: Kevin Beggs (Ire), TMO: Simon McDowell (Ire), Citing Commissioner: John Byett (Eng)
• Toulouse have lost just one of 15 home games against Welsh opposition in this competition, losing to Llanelli Scarlets back in 2006.
• Conversely Ospreys have won just one of 11 trips to France in the Heineken Cup, a 28-21 victory over Bourgoin in 2008.
• Alun Wyn Jones has won a competition joint-high 14 lineouts for Ospreys this season.
Pool 3: Zebre v Harlequins
Saturday, 8th December 2012, Kick off: 14:35, Stadio XXV Aprile
Referee: Neil Paterson (Sco), Assistant Ref: Andy Macpherson (Sco), Assistant Ref: Bob Nevins (Sco), TMO: Jim Yuille (Sco), Citing Commissioner: Francois Guers (Fra)
• Harlequins average five successful penalty goals per game so far this season, a tournament high.
• Zebre average 202 metres gained per game, the lowest in the tournament this season.
• Harlequins have averaged more time in possession than any other side in the tournament sofar this season (19: 30).
• Harlequins have won three of their last four away games in this competition, this run including a memorable win over Toulouse last season.
Pool 6: Sale Sharks v Toulon
Saturday, 8th December 2012, Kick off: 15:40, Salford City Stadium
Referee: Leighton Hodges (Wal), Assistant Ref: Gwyn Morris (Wal), Assistant Ref: Wayne Davies (Wal), TMO: Nigel Whitehouse (Wal, Citing Commissioner: Maurizio Vancini (Ita)
• Toulon have won 12/12 scrums on their own put in so far in the Heineken Cup.
• Andy Powell has made eight offloads in just 80 minutes of action so far this season, no other player has made more than this.
• Sale have lost four of their last five games against French sides in the Heineken Cup, beating only Clermont Auvergne in 2009.
• Toulon won on their only other Heineken Cup away game in England, beating London Irish in December 2010, 19-13.
Pool 1: Munster Rugby v Saracens
Saturday, 8th December 2012, Kick off: 18:00, Thomond Park
Referee: Romain Poite (Fra), Assistant Ref: Christophe Berdos (Fra), Assistant Ref: Cyril Lafon (Fra), TMO: Jean-Pierre Pellaprat (Fra), Citing Commissioner: Douglas Hunter (Sco)
• Saracens have a 100% success rate at the lineout this season (on their own throw), retaining ball on all 23 throws so far as well as stealing a competition high six opposition throws.
• Munster are also joint-top of the lineouts stolen chart, averaging three per game themselves.
• Munster have retained possession at 97% of rucks and mauls, a tournament high.
• Charlie Hodgson is the top points scorer after two rounds, scoring 40 so far including one try, seven conversions and seven penalties.
Pool 1: Racing Metro 92 v Edinburgh Rugby
Saturday, 8th December 2012, Kick off: 19:00, Stade Yves du Manoir
Referee: Peter Fitzgibbon (Ire), Assistant Ref: Stuart Gaffkin (Ire), Assistant Ref: John Carvill (Ire), TMO: Dermot Moloney (Ire), Citing Commissioner: Gordon Black (Ire)
• Edinburgh are the only team yet to register a point in this year's tournament.
• Edinburgh have lost 11 lineouts on their own throw so far this season and have a success rate of just 68%, the worst figures in the tournament.
• Racing Metro's 7.5 penalties conceded per game is a tournament low this season.
• Racing Metro are one of four teams to have won all of their scrums at their own put in so far this term.
Pool 6: Cardiff Blues v Montpellier
Sunday, 9th December 2012, Kick off: 12:45, Cardiff Arms Park
Referee: John Lacey (Ire), Assistant Ref: Leo Colgan (Ire), Assistant Ref: Michael Black (Ire), TMO: Peter Ferguson (Ire), Citing Commissioner: Eddie Walsh (Ire)
• Cardiff have missed the most tackles in the Heineken Cup so far this season, missing 42 in their two pool matches so far. Their completion rate of 85% is the lowest in the tournament.
• Montpellier's six lineout steals is a joint-high this season.
• Montpellier's scrum is particularly strong this season having won all 17 of their put-ins so far.
• Cardiff have lost their last three Heineken Cup games, the last time they lost four in a row was in 2006/07.
Pool 2: Leicester Tigers v Benetton Treviso
Sunday, 9th December 2012, Kick off: 15:00, Welford Road
Referee: Paul Gauzere (Fra), Assistant Ref: Laurent Cardona (Fra), Assistant Ref: Stephan Pomarede (Fra), TMO: Gilles Cogne (Fra), Citing Commissioner: Yann Le Dore
• Treviso have a 100% success rate at goal kicking so far in the Heineken Cup this season.
• Treviso have been shown four yellow cards and conceded 37 penalties, both of which are tournament highs.
• Leicester have forced fewer turnovers than any other team in the competition, averaging two per game so far.
• Leicester are unbeaten at home in the Heineken Cup since losing to Munster back in October 2006.
Pool 5: ASM Clermont Auvergne v Leinster Rugby
Sunday, 9th December 2012, Kick off: 16:00, Stade Marcel Michelin
Referee: Nigel Owens (Wal), Assistant Ref: Sean Brickell (Wal), Assistant Ref: Jon Mason (Wal), TMO: Derek Bevan (Wal), Citing Commissioner: Alan Mansell (Eng)
• The French team average the most carries and have gained the most ground per match so far, racking up 134 carries per match at a gain of 645 metres.
• Conversely, the best attack in the competition meets the best defence as Leinster have missed only eight tackles in 160 minutes of rugby so far. They have completed 97% of attempted tackles.
• Clermont's Damien Chouly has made a competition high 33 carries so far this season.
• If Gordon D'Arcy plays, he will make his 88th appearance in the Heineken Cup and will move ahead of Shane Horgan as the Leinster player with the most tournament appearances.
Sale Sharks v. Toulon - Salford City Stadium, Saturday 8th December 2012 (3.40pm). Tickets 08444 994 994 or book through our online ticketing system.
No parking remaining at the stadium: you are recommended to travel by public transport. We are advised that shopping traffic for the Trafford Centre will be heavy, so allow plenty of time. Have a look at our travel plan for the game.