All Blacks midfielder Jordie Barrett has wasted little time endearing himself to Leinster rugby fans, with a starring role against Bristol in his debut for the Irish club.

Entering the game from the bench at halftime, Barrett scored a try and created another in his team's 35-12 European Champions Cup win.

With the two teams locked 7-7 at the break, the injection of the Kiwi and several Ireland internationals helped break the contest wide open in the second 40 minutes.

Barrett provided the final pass for Sam Prendergast's first try — delaying his offload to draw the defence before putting the first-five into space near the line.

Three minutes later, he put his own name on the scoresheet — again putting his markers in two minds before rocketing through a gap to score.

A third try within five minutes — two from Prendergast, who converted them all — swung the match decisively to the visitors.

"Ciaran [Frawley] went off with a knock to his back at half-time, so it was an amazing experience to be able to bring him off the bench," said Leinster coach Leo Cullen of Barrett.

"It's taken a lot of work to get him here... so he’ll play a big part over the course of the season. Quality person; quality player.

"We weren’t sure how we’d get him up and running. We thought it was sensible to have him on the bench, as he figures out a number of things this week and the tail end of last week.

"Hopefully, he kicks on, goes from strength to strength. When you bring someone in from the outside, you just want to make sure they add.

"He has an interesting connection to Leinster, going back to when he was a youngster. He had a fascination to here, so we’re lucky to have him and hopefully he’ll be able to have a good run with us."

Barrett was granted the Irish sabbatical as part of his long-term All Blacks contract extension in April. Ireland holds childhood memories for Barrett, after father Kevin moved the family there to play for the Athlone club and work on a local farm in 2000.