It has been a poor evening for the Irish provinces in the Guinness PRO12, with both Munster and Ulster falling to defeat.
Munster surrendered top spot in the table with a 21-18 defeat in Glasgow. Anthony Foley's side failed to score in the second half against a determined Warriors side.
The defeat came after a great first half for the Irish team. Munster were 9 points ahead going into the second half, thanks to tries from Robin Copeland and JJ Hanrahan.
Warriors came back fighting, with Leone Nakarawa and man of the match Jonny Gray scoring the tries that pushed Glasgow ahead.
The win secured Warriors a temporary place at the top of the PRO12 table - a lead that was to prove short-lived due to Ospreys' 31-20 bonus point defeat of Ulster at Liberty Stadium.
A penalty for Ian Humphreys secured Ulster their only three first half points, compared to 17 for Ospreys.
Second half tries for Tommy Bowe and Rob Herring - both converted by Humphreys - narrowed the gap, but were not enough to close it.
A total of four tries - including two from Rhys Webb - all converted meant Ospreys led by a comfortable 11 points when the final whistle blew. They now sit a single point above Warriors on the PRO12 table, with the four Irish provinces occupying third (Munster), fourth (Leinster), fifth (Ulster) and sixth (Connacht) places.
