Leinster head coach Leo Cullen was pleased with his side's resilience as they came from nine points adrift at half-time to dispatch Leicester in Welford Road.
Seeking back-to-back wins over Premiership opposition, the visitors trailed 15-6 after an error-ridden first half display, Adam Radwan seizing on a dropped ball from Robbie Henshaw in the Leicester 22 to charge away and score the opening try.
Wales wing Ollie Hassell-Collins added the second on the cusp of half-time after a clever cross-kick from Ben Searle.
However, Cullen's side reacted impressively after the restart, gaining supremacy at the breakdown and in the forwards.
Their first try had a touch of fortune about it, Jamison Gibson-Park pilfering a ball that slipped out of the back of the scrum and darting over in the corner.
After Harry Byrne, unerring from the kicking tee, edged them in front with a second half penalty, Dan Sheehan essentially assured the visitors of the win, powering over from an attacking lineout.
"I'm very pleased how we stuck at it, although if we had taken our opportunities, we would have made it easier for ourselves," Cullen said.
"It’s an incredibly tough place to come and although we played with great intensity, they were very dogged and made life difficult for us.
"We had a lot of early disruption with Tadhg (Furlong) feeling unwell on leaving the hotel and then losing two players in the first 11 minutes.
"We then had a try harshly ruled out but we showed great composure even though we were trailing 15-6 at half-time.
"We had a lucky break when the ball comes out of the scrum but Jamison finished well and it was a great result for us in the difficult conditions as it was very greasy out there."
Tigers Director of Rugby Geoff Parling admitted his frustration after the result, suggesting that his side got a raw deal from the officials.
"I'm proud of the way the group stood up for each other," Parling told Premier Sports. "I didn't think things went for us in the game. I didn't. We just got to learn when we're not getting the calls that we deserve, what can do to really tighten up.
"I'm incredibly proud of the effort as our defence was outstanding, the best performance of the season in that area, but I’m frustrated as the game was there for us.
"A lot of people had written us off before the game and it would have been an incredible day had we won as Leinster haven’t lost a European pool game for four years.
"Going toe-to-toe with them gives our fans hope and belief for the future but we need to double-down on our accuracy.
"The way the competition is set up, we are still in with a chance of progressing."
