With the road to the much-anticipated 2018 Bilbao finals certain to be clearer when the pool stages are completed, the exact dates, kick-off times and broadcast coverage for the key fixtures have been announced on Thursday, 21 December.
The Dragons will face Bordeaux away at Stade Chaban-Delmas on Saturday 13 January at 8pm GMT (9pm local time) followed by the return match at Rodney Parade on Saturday 20th January at 3pm.
In the Champions Cup, Pool 5 leaders, Bath Rugby, will get Round 5 underway at the Recreation Ground against the Scarlets, who are just one point behind in the standings, on Friday, 12 January live on BT Sport.
La Rochelle will travel to take on Ulster Rugby at the Kingspan Stadium in a crunch tie at the top of Pool 1 on Saturday, 13 January on Sky Sports, while Racing 92 and Munster Rugby will clash on Sunday, 14 January also live on Sky Sports when the magnificent new U Arena stages a Champions Cup game for the first time.
With the five pool winners and the three best runners-up from both competitions set to book their places in the quarter-finals, the fact that RC Toulon last season, and the Exeter Chiefs in 2015/16, reached the knockout stage of the Champions Cup on 16 points, indicates that there is still much to play for in the closing rounds.
With the Round 6 fixtures in the same Champions Cup pools kicking off at the same time, the eight quarter-finalists will be known on Sunday, 21 January following the concluding games in Pool 1 between Wasps and Ulster Rugby at the Ricoh Arena, and between La Rochelle and Harlequins at Stade Marcel-Deflandre.
The Challenge Cup returns on Friday, 12 January with the high-profile clash of Pool 4 leaders, Edinburgh Rugby, and holders, Stade Francais Paris, at Myreside, while Agen host Gloucester Rugby in Pool 3 at Stade Armandie.
Cardiff Blues and Toulouse go head-to-head on Sunday, 14 January live on BT Sport in a reprise of the inaugural 1996 European Cup final at the historic Cardiff Arms Park, and Challenge Cup fixtures will be staged for the first time in Georgia in Round 6 when Enisei-STM play Newcastle Falcons, and Krasny Yar meet London Irish in a double-header at Tbilisi's Avchala Stadium on Saturday, 20 January.
Round 6 will be wrapped up later the same day with the return fixture between Edinburgh and Stade Francais Paris at Jean Bouin.
Knockout stages
Quarter-finals: 29/30/31 March - 1 April 2018
Semi-finals: 20/21/22 April 2018
2018 Bilbao finals
Challenge Cup final - San Mamés Stadium; Friday, 11 May (21.00)
Champions Cup final - San Mamés Stadium; Saturday, 12 May (17.45)
