The Welsh region must have fancied another field day after their seven try mauling of Ulster last weekend, but it was a much tougher task on the Ravenhill turf.
Marshalled by Heineken man of the match Rory Best, Ulster were competitive at the set piece and crucially at the breakdown, forcing the Ospreys into a number of handling errors in the early stages.
Gone was the swagger shown at the Liberty Stadium and it was a nervy performance that won’t have worried Pool rivals Gloucester. However, they did score the first points of the match through James Hook penalties on 12 and 15 minutes.
Young fly half Niall O’Conner got one back moments later and when Simon Danielli scored a wonder try moments before the break, Ravenhill started to believe.
The Ospreys did eventually take control of the match in the second half when the industrious Justin Marshall scored a training ground line-out move. Hook coverted and added a penalty to finish the scoring for the match.
Ulster lost two men to the sin bin in the second period and found themselves short of attacking chances. The Ospreys will take this win, which keeps them on collision course with Gloucester for a place in the final eight.
