Saracens made it two wins from two in the European Champions Cup on Saturday as they overcame a spirited Ospreys side 36-34 in a thriller at Allianz Park.
The Premiership leaders and defending champions found themselves 10 points behind at the half-hour mark as the Welsh province - who were forced into late changes after back injuries to Justin Tipuric and Dan Lydiate - made a roaring start.
Sarries showed their class in the final minutes of the half, though, Schalk Brits' converted try making it 17-17 at the break.
Second-half scores from Liam Williams and Nick Tompkins completed Saracens' comeback, securing a bonus point to top Pool 2 despite a late fightback from Ospreys.
The other game in the group was marred by a sickening injury to Clermont Auvergne's Camille Lopez, the France international fracturing the tibia in his left leg under a tackle from Piers Francis. Clermont expect Lopez to be out for "many months" - the fly-half set to have surgery later on Saturday.
Lopez's injury soured a 24-7 victory for the French side over Northampton Saints, the Premiership outfit also seeing Dylan Hartley yellow carded for catching Rabah Slimani in the face during a ruck.
Benetton Treviso's hopes of a rare Champions Cup win were ended by a last-gasp Francois Trinh-Duc penalty as Toulon snatched came out on top 30-29.
The Italians' last triumph in this competition came in January 2015 but the boot of Ian McKinley had them on the verge of a sensational result against the three-time champions in Pool 5 until Trinh-Duc came to the rescue for the Top 14 heavyweights.
Leicester Tigers bounced back from their opening defeat to Racing 92 with a stunning victory over Castres in Pool 4, the hosts scoring seven tries at Welford Road in a 54-29 win.
A sensational opening 40 minutes all-but secured the result as Leicester amassed 35 points to Castres' three, Telusa Veainu scoring a hat-trick as the Premiership side secured a bonus point.
Munster are level with Leicester on six points thanks to a narrow 14-7 success over Racing, the Top 14 side occupying third place just a point adrift after the opening two matches.
Jonathan Sexton put on a kicking masterclass on his return from injury as Leinster dented Glasgow Warriors' hopes qualifying from Pool 3 with a 34-18 win.