LISBON • Renato Sanches was grateful to Benfica fans who gave him a standing ovation after he scored against his old club to inspire Bayern Munich to a 2-0 win in their opening Champions League Group E fixture on Wednesday.

The Portuguese midfielder, who has endured a torrid few years since leaving Benfica for Munich as an 18-year-old after Euro 2016, capped a fine performance in Lisbon with his first Bayern goal.

"I'm so happy to have had a night like this in Lisbon, and I want to thank the Benfica fans," Sanches told Sky Sports. "It was a very special moment for me and I enjoyed it a lot."

His second-half goal also crowned a perfect Champions League debut for Bayern coach Niko Kovac.

Sanches, who hardly played for Bayern before he was loaned out to Swansea City last season, earned a rare start with Thiago Alcantara injured.

The 21-year-old midfielder emerged as a teenage sensation following Portugal's Euro 2016 win, but Bayern fans had seen little of him before Wednesday.

The Bundesliga leaders, who have won all their competitive matches so far this season, opened accounts after 10 minutes when Robert Lewandowski collected David Alaba's cutback before evading his marker's challenge to fire home.

In the 54th minute, Sanches started the move with a sensational 40-metre sprint before finishing it off with a tap-in to the stadium's approval.

"It has not always been easy for Renato since he came to Bayern but tonight he had a massive game. I take my hat off to him," said right-back Joshua Kimmich.

Benfica, who have not scored more than once in their last 10 Champions League games on home soil, failed to test Bayern goalkeeper Manuel Neuer, with numerous shots fired wide.

AGENCE FRANCE-PRESSE, REUTERS