Wales international Dan Biggar played his first game for Northampton Saints as English Premiership side completed a 26-13 victory over Ospreys in the pre-season friendly in Bridgend.
Craig Gilroy scored a double as Ulster thumped Ospreys 35-17 in the Pro 14 play-off in Belfast to book a place in the next season of European Champions Cup.
Ospreys kept their hope of European Champions Cup qualification alive as they went on to seal a 39-10 bonus point victory over Connacht in their Pro 14 clash in Swansea on Friday.
A strong second-half upsurge helped Bath Rugby secure a home semi-final in the Anglo-Welsh Cup with a 32-19 bonus-point win over the Ospreys at the Liberty Stadium on Friday.
Clermont Auvergne secured a home quarter-final berth in the European Champions Cup following a 24-7 win over Ospreys at Stade Marcel-Michelin on Saturday.
An injury to Billy Vunipola put the defending champions Saracens in trouble as they went on to draw the European Champions Cup encounter against Ospreys 15-15 at Liberty Stadium.
Saracens have received a major boost ahead of their upcoming European Champions Cup clash against Ospreys with Wales international Liam Williams declared fit.