Leinster have plenty to work on
Leinster skipper Jamie Heaslip warned his side they have "still got a lot to work on" despite picking four points on the road against the Ospreys.
The three-time champions came from behind to stun the home side, playing in front of a season high crowd of more than 12,000, and deny them a losing bonus point with almost the last kick of the game.
The two teams had played out a high-scoring draw in Dublin earlier in the season, but this was an uncompromising, highly physical encounter in which the Leinster defence came out on top.
"They got one over us at RDS and it's nice to come here and put one over them and get one back. There was a lot of attrition out there and it wasn't easy. We've got to rest up now before next week," said Heaslip.
"We got taught a lesson by Munster in terms of being first to the breakdown last week We know that quick ball wins games and we gave that to our back line and we caused some damage.
"But the Ospreys kept going and going and that game could have gone either way in the end. It is always tight between us and we won the war of attrition at the tail end of the first half and in the second.
"We're happy with the win but we've got a lot to work on for next week. We're a week by week team, and we don't look too far ahead, but it would be nice to get out of our Pool," he added.
Man of the Match Sean O'Brien, who scored the game's only try, claimed it had taken last season's Challenge Cup champions until now to find their feet after so much change in the summer.
"With a new coaching staff and new players it takes a bit of time to gel, especially as we have some new systems. It has taken five or six games to get to where we are now," said O'Brien.
"Everyone gets very excited at European Cup time. The European Cup is something we want to win every year and after last year we are a little bit sore about certain things and we want to put that right.
"We said trust the systems tonight. We stuck to our task and it worked for us."