A round-up of the weekend's Champions Cup clashes...
Saturday's action
Saracens complete perfect pool campaign
Saracens overcame the late withdrawal of Owen Farrell to advance into the Champions Cup quarter-finals as top seeds by beating Glasgow 38-19.
Farrell was replaced by Alex Goode at fly-half after being forced to undergo surgery to repair a damaged thumb tendon on Saturday morning that is expected to rule him out for seven to 10 days.
The prognosis means England's captain will be available for the Guinness Six Nations opener against Ireland on February 2, although his participation in training until then will be severely limited.
In his absence Saracens completed a perfect qualifying campaign in Pool Three with six wins from as many matches to ensure they will face the bottom seeds - who could be fellow qualifiers Glasgow - in the last eight.
The opening half-hour at Allianz Park was lit up by six tries but the avalanche of points dried up thereafter and it was not until 69th minute that the scoreboard was troubled again.
Saracens, who were lifted by the return of skipper Brad Barritt from a head injury, broke the deadlock at 24-19 when man of the match Maro Itoje touched down to secure the bonus point.
Glasgow were hit by the loss of Scotland forwards Jonny Gray and Ryan Wilson to second-half injuries that will concern Gregor Townsend and the Warriors were superb in a feisty European clash despite the lop-sided final scoreline.
Racing 92 book home quarter
Racing 92 booked a home quarter-final with a 46-33 bonus-point victory over the Scarlets in Paris.
A brace of tries from Simon Zebo plus a try apiece from Juan Imhoff, Henry Chavancy, Virimi Vakatawa and Teddy Iribaren was enough to overcome a resilient Scarlets side.
The Welsh region scored three tries of their own with Johnny McNicholl crossing twice and Steff Evans also touching down.
Munster edge past Exeter
Munster came through a thunderous test of their Heineken Champions Cup credentials as they ended Exeter's hopes with a 9-7 defeat in front of a capacity Thomond Park crowd.
Joey Carbery's 72nd-minute penalty, from all of 44 metres, decided this Pool Two shootout in Munster's favour as they advanced to a record 18th European Cup quarter-final.
Don Armand scored the game's only try from a 12th-minute maul, giving Chiefs a 7-6 half-time lead in their pursuit of a result that would see them finish top of the table.
While the defence-dominated phases meant there was no chance of pressing for four tries, Exeter could not edge Munster out of losing bonus-point range either and, in the end, Ireland fly-half Carbery knocked the Gallagher Premiership leaders out with his third successful penalty of the night.
Despite claiming top spot in the pool and maintaining their excellent home record against English opposition in Europe, Munster will be away from home in the last eight.
The opposition is likely to be Guinness PRO14 rivals Edinburgh, who won Pool Five. That will be confirmed on Sunday afternoon depending on Leinster's result at Wasps.
Ulster comeback to stun Tigers
Ulster recovered from a 13-0 deficit to beat Leicester and claim a European Rugby Champions Cup quarter-final place for the first time since 2014.
Dan McFarland's side trailed 10-0 at half-time - and 13-0 soon after - but second-half tries from Marty Moore and Robert Baloucoune ensured they clinched a 14-13 victory at Welford Road to reach the final eight as one of three best-placed runners-up.
The permutations were clear for Ulster, a win at Leicester would guarantee them a quarter-final berth in Europe's elite rugby competition for the first time in five years.
It was a cagey and error-strewn first-half from both sides with opportunities few and far between.It took 32 minutes for the game's first score. Lock Henderson was caught off his feet at the ruck - with Ford adding the three points from a comfortable range for the England International.
Ulster wasted their best opportunity after miscommunication between the forwards at the breakdown deep inside Leicester's 22, which allowed the hosts to clear.
The Tigers added further points on the cusp of half-time after Ford - impressing at fly-half in the midst of Owen Farrell's Six Nations injury scare - grubber-kicked accurately with Matt Toomua slamming down for the try.
Ford kicked the conversion from out wide to give Leicester a 10-0 interval lead and he extended the advantage from close-range minutes after the break.
However, Ulster soon clicked into gear to mount their comeback. They edged their way back into contention after a string of close attempts, and eventually found their reward when Moore peeled off the side of a driving maul to score - with John Cooney drilling the conversion.
Ulster - and their strong away support - were buoyed by the breakthrough and minutes later took the lead. Burns chipped to the wing and a charging Baloucoune collected before sprinting behind the posts.
Cooney kicked to put the visitors ahead - a kick which ultimately sealed their fate.
At the other end Baloucoune put in a lung-busting stop to halt a rampant Greg Bateman from a golden scoring opportunity and Rory Best and Andy Warwick later combined to snatch a crucial turnover on the five-metre line with the Tigers lurking.
Ulster had to remain wise and resolute to hang on in the final minutes but they did enough to get over the finishing line, with Darren Cave kicking to touch to cap a memorable day for Irish rugby - which could see Ulster taking on rivals Leinster in the next round.
Cardiff Blues end European campaign on a high
Cardiff Blues ended their disappointing European Champions Cup campaign by completing the double over Lyon with a convincing 33-14 win at the Arms Park.
The two wins over the French side were Blues' only successes in the competition, which saw them end up finishing third in Pool Three with Lyon remaining pointless.
Lyon surprisingly led at the interval but Blues totally dominated the second half to score 21 unanswered points.
Aled Summerhill scored two tries for Blues, Owen Lane, Lewis Jones and Tomos Williams one apiece, with Gareth Anscombe converting four.
Lyon's try came from Xavier Mignot which Alexis Palisson converted and there was also a penalty try awarded.
Castres strike late to beat Gloucester
Gloucester head coach Johan Ackermann felt his side should have beaten Castres to finish their Champions Cup Pool Two campaign on a high, but was nevertheless proud of his players following a 24-22 defeat at Stade Pierre Fabre.
An inexperienced Cherry and Whites, showing 10 changes from the one that lost to Munster at Kingsholm last week, were leading by three points and had stolen possession as the clock ticked into the red.
Yet rather than being booted into touch, the ball was hoofed upfield, giving Castres one last shot from nearly 70 metres out. It was a chance the French side took as Ma'ama Vaipulu crossed for a dramatic end to the dead-rubber match.
"We probably should have won it," Ackermann said.
"We will look back at a few opportunities that we left out there, but it's a tough place to come and the performance was very good.
"We came out tonight and gave a fight. That was what we asked for."
Friday's action
Falcons edged out as Toulon snatch victory
Toulon edged an entertaining but meaningless Heineken Champions Cup pool five clash at Newcastle 27-24.
There were six scintillating tries shared in an exciting, error-strewn match, including two in the opening five minutes and three more in a frantic three-minute spell late in the second half.
Newcastle fought back from 20-10 down to lead 24-20, only to immediately concede a heart-breaking winning try to Bastien Soury.
Edinburgh secure home quarter-final and send Glasgow through in process
Edinburgh sealed Heineken Champions Cup quarter-final places for themselves and Glasgow with a 19-10 victory over Montpellier.
The win secured top spot in Pool 5 and a home contest for Richard Cockerill's side in the last eight, and ensured Glasgow will finish as one of the three best runners-up if they lose their group decider against Saracens in London on Saturday.
Darcy Graham's try just after the hour mark was just reward for a spell of intense pressure that proved the key passage of play in front of 11,802 fans at BT Murrayfield - a Scottish record for a European pool match.
Montpellier - coached by former Scotland boss Vern Cotter - had got themselves back in the contest following three penalties from Jaco Van Der Walt, with a try from Jacques Du Plessis on the stroke of half-time.
But the penalty that put them ahead seven minutes into the second half jolted the hosts back into the ascendancy and they went on to seal an historic achievement for Scottish rugby as both clubs reached the knockout stages of Europe's premier competition for the first time together.