Paris - Defending champions Saracens overcame a suspected broken arm for Billy Vunipola and 43 minutes with 14 men to notch up a drama-filled 27-24 victory over Racing 92 on Sunday to set up a European Champions Cup quarter-final at Irish giants Leinster.
Mark McCall's side, who accepted Saturday that they would be relegated from the English Premiership to the second-tier Championship at the end of the season for salary cap breaches, failed to bag a winning bonus point, meaning their qualification for the Euro quarters depended on Gloucester not gaining a bonus-point or high-scoring win over Toulouse in Sunday's late game.
That was not to be as Toulouse ran in five tries in a convincing 35-14 victory to set up a home quarter-final against Ulster.
Racing will travel to Clermont and Exeter host Northampton in the two other quarter-finals.
McCall said pre-match that Saracens' promised relegation had at least given the club "clarity on their future". On the pitch, the star-studded side stepped up despite the intentions of a Racing side that rarely threatened with ball in hand but which snatched every opportunity that came their way.
"Amazing!" said Saracens' backrower and man-of-the-match Ben Earl.
"We knew we had to do our talking on the pitch today.
"The experienced heads in the changing rooms spoke a lot about our plan.
"With what's gone on this week, our focus was just Europe, to win something, the best competition in the world arguably."
Saracens enjoyed a whirlwind forward-driven start, ever-present lock Maro Itoje piling over for a try in under two minutes, England skipper Owen Farrell hitting the simple conversion.
But the home outfit suffered a blow with England No 8 Vunipola taken off with a suspected broken forearm - a third of his career - after just six minutes, giving Eddie Jones a headache as he prepares to name England's Six Nations squad on Monday.
Billy's propping brother Mako Vunipola span off the back of an attacking lineout maul for a try shortly after, Farrell again converting.
Against the run of play, however, Racing fired back with two opportunistic tries either side of a Farrell penalty.
Firstly, Fiji-born France centre Virimi Vakatawa latched on to a loose ball to sprint in unmolested for a soft try, Finn Russell converting to keep the Parisians in the contest.
Then Farrell was guilty of gifting Louis Dupichot an intercept try as he sought to go wide, Teddy Iribaren kicking the extras.
In-form Vakatawa crossed for his second, and Racing's third, on the half-hour mark, cutting through an unravelling defence after a great Russell break.
Saracens suffered another hammer blow on the stroke of half-time when giant Australian lock Will Skelton was red carded for a high, no-arms tackle on Racing fullback Brice Dulin.
Iribaren extended Racing's lead early in the second period with a long-range penalty, but Sarries weren't done.
Duncan Taylor offloaded to Earl who accelerated down the line and popped the ball inside to Itoje for a fine try, Farrell converting to make it 24 points apiece.
With just 11 minutes to play, Racing's South African-born flanker Bernard Le Roux saw yellow for a needless late tackle on Farrell, but Eliot Daly sent his penalty effort wide.
Farrell had the final word, booting a penalty after Racing captain Henry Chavancy drifted offside to make sure the defending champions kept in the hunt.
"This game really showed the resilience and how tough this team is," said Itoje.
On Saturday, four-time champions Leinster assured themselves of top seeding in the quarters after making it six out of six for an unassailable 28 points to top Pool 1 with an 18-0 win over Treviso.
European Champions Cup results on Sunday, the sixth and final round of pool matches:
Munster (IRL) 33 Ospreys (WAL) 6
Saracens (ENG) 27 Racing 92 (FRA) 24
Montpellier (FRA) 35 Connacht (IRL) 29
Toulouse (FRA) 35 Gloucester (ENG) 14
Played on Saturday:
Treviso (ITA) 0 Leinster (IRL) 18
Lyon (FRA) 24 Northampton (ENG) 36
Exeter (ENG) 33 La Rochelle (FRA) 14
Sale (ENG) 7 Glasgow (SCO) 45
Harlequins (ENG) 19 Clermont (FRA) 26
Ulster (IRL) 22 Bath (ENG) 15
Quarter-finals: April 3-5
Leinster v Saracens, Clermont v Racing 92, Toulouse v Ulster, Exeter v Northampton
Semi-finals: May 1-3
Leinster or Saracens v Clermont or Racing 92, Toulouse or Ulster v Exeter or Northampton
Final: May 23 at Marseille, France