The host was seeking revenge after its 8-2 loss against the same opponent in the 2019-2020 quarter-finals, but Bayern proved far too strong once again in the Group E opener between the two heavyweights.

Muller opened the scoring in that humbling defeat for Barca 13 months ago and did likewise in the first half at Camp Nou before Lewandowski's simple finish gave Bayern breathing space early in the second period.

Lewandowski doubled his tally late on to seal a routine win that moves the German champion into top spot after the first round of fixtures, while Barca sit bottom after Dynamo Kyiv and Benfica played out a goalless draw.