Chris Wyles scored a key late try for Saracens to help spark his professional club to a 31-26 European CUp victory over the Ospreys of Wales.
With the victory, Saracens moved to 2-1 and top of Pool 5 in the Heineken Cup, while the Ospreys dropped to 1-1-1.
Biarritz and Takudzwa Ngwenya were upset by Treviso in Pool 5 and dropped to 1-2.
Playing before 41,000 at Wembley Stadium, Saracens almost scored in the first two minutes, as Wyles was just pushed into touch at the corner.
But the Watford club had the run of play for most of the match, getting three Owen Farrell penalties and a try from Rhys Gill and Ernst Joubert to lead 23-13.
But the Ospreys looked too dangerous for Saracens to be comfortable, so they needed Wyles's try to lead 28-16.
Good, deep attack lines set up the try, with hooker Schalk Brits slipped a backhanded reverse pass to Wyles to set the wing up for the try.
"A moment of briliance by Schalk and I just managed to power over there," said Wyles after the game. "I feel pretty happy about things. We didn't defend our lead that well ... but a great victory and another victory for us at Wembley."
Ospreys, run by former USA Head Coach Scott Johnson, came back, but not quite enough.
Also in European action Saturday, Samu Manoa started at No. 8 for Northampton, scored a try and was, overall, outstanding. But the Saints lost 41-22 to Castres.
In Amlin Challenge Cup action, Agen lost 29-14 to Sale. Kevin Swiryn started at right wing for Agen. Stade Francais won easily 57-0 over Baca Monte Crociati. Scott LaValla did not play.