Bayern Munich kicked off their Champions League campaign by easing to a 3-0 victory over Red Star Belgrade on Wednesday in a one-sided Group B encounter.
Kingsley Coman headed them into the lead in the 34th minute from a fine Ivan Perisic cross and the Bundesliga's leading scorer Robert Lewandowski slid in for the second goal in the 80th.
Thomas Mueller, who became the club's record Champions League appearance maker when he came on as a substitute for his 106th game in the competition, volleyed in his first goal of the season in stoppage time.
Bayern, who stretched their unbeaten run in Champions League group stage home matches to 16, carved out chance after chance and twice hit the woodwork, while the Serbs, who battled through qualifying, were largely toothless up front.
In the group's other game, last season's runners-up Tottenham Hotspur squandered a two-goal lead to draw 2-2 away to Greek club Olympiakos Piraeus on Wednesday.
Tottenham silenced the raucous crowd with two goals in four minutes midway through the opening half, first with Harry Kane's well-struck penalty and then a stunner by Lucas Moura.
Olympiakos, who had conceded only once in nine games in all competitions so far this season, halved the deficit through Daniel Podence shortly before halftime.
The hosts levelled it up after 54 minutes when Mathieu Valbuena beat fellow Frenchman Hugo Lloris from the penalty spot after some sloppy play by the visitors.
Tottenham looked the more likely winner in the closing stages with Dele Alli and Erik Lamela squandering chances.
While it was an improvement on their start in last season's ultimately memorable Champions League campaign, when they lost their opening two matches, Tottenham will be disappointed at their failure to protect their lead.
They will need to be far more clinical when they host Bayern Munich in their second game. Olympiakos will travel to Red Star Belgrade next.
"When you go 2-0 up after 30 minutes you are in a great position, after that I thought we controlled the game whereas before we didn't play well but scored two goals," Kane said.
"The goal just before halftime changed the momentum and it's disappointing from our point of view. We have to improve.
"We wanted to get off to a winning start and put ourselves in a great position."
In Group C, Manchester City put aside their recent Premier League setback, delivering a comfortable performance in a 3-0 win at Shakhtar Donetsk.
Pep Guardiola's side, beaten by Norwich City on Saturday, brought in their Brazilian former Shakhtar midfielder Fernandinho as a makeshift central defender to replace the injured John Stones.
But there was to be no real test of City's back line as the English champions dominated, taking the lead in the 24th minute through Riyad Mahrez, who slotted home after Ilkay Gundogan's shot came out off the post.
Shakhtar quickly had a chance to go level after a superb run from Taison who found Junior Moraes but his tame shot was well dealt with by Ederson.
City doubled their lead in the 38th minute with Mahrez finding Gundogan at the end of a trademark City passing move and the German clipped home to make it 2-0.
The Ukrainian side struggled to break up City's possession play in midfield and while there was a relaxed tempo from Guardiola's side, the outcome was never in doubt.
Gabriel Jesus made it three in the 76th minute after Kevin De Bruyne led a swift counter-attack and slipped in the Brazilian who made no mistake.
There was some good news on the injury front for City with French left-back Benjamin Mendy coming on as an 83rd-minute substitute, for his first appearance since April.