Barcelona plunged even further into crisis on Wednesday with a thumping Champions League defeat at Benfica while holders Chelsea were beaten by Juventus, but Cristiano Ronaldo grabbed a precious last-gasp winner for Manchester United.

Ronald Koeman's Barcelona side already look at real risk of an early exit from this season's Champions League after suffering a second 3-0 defeat in as many games in Group E and finishing the match in Lisbon with 10 men.

Uruguayan forward Darwin Nunez starred for Benfica, opening the scoring early on and then hitting the post early in the second half. He later completed the rout from the penalty spot following a Sergino Dest handball, while in between Rafa Silva also netted for the Portuguese former European Cup winners.

Barca are rock bottom of their group while Bayern followed their victory at the Camp Nou a fortnight ago with a 5-0 home win over Dynamo Kiev, with Robert Lewandowski's first-half brace setting the Bavarians on their way.

Lewandowski, who netted the opener from the penalty spot, now has a career tally of 77 Champions League goals, third in the all-time list behind Ronaldo and Lionel Messi.

Serge Gnabry, Leroy Sane and Eric Maxim Choupo-Moting added further goals after the break for a rampant Bayern.

Chelsea will still be expected to qualify for the last 16 despite losing 1-0 to Juventus in Turin, with Federico Chiesa scoring the only goal of the game 10 seconds into the second half.

The star of Italy's Euro 2020-winning side latched onto Federico Bernardeschi's assist to beat Edouard Mendy and give Massimiliano Allegri's team a second straight win in Group H.

Juve are still adapting to life since the return of Allegri as coach and the departure of Ronaldo, but this could be a formative result for them against the holders.

"We gave a cheap goal away, and that made things more complicated for ourselves," said Chelsea coach Thomas Tuchel.

Ole Gunnar Solskjaer admitted Manchester United "got lucky" after Ronaldo marked his record-breaking 178th Champions League appearance with a 95th-minute winner to beat Villarreal 2-1 at Old Trafford.

The five-time Ballon d'Or winner had barely threatened until he fired past Geronimo Rulli for his fifth goal in as many games since returning to United.

Solskjaer's men were staring down the barrel of another embarrassing group-stage exit from the Champions League after deservedly falling behind early in the second half to Paco Alcacer's smart finish.

Alex Telles' stunning strike quickly leveled, but they looked set to drop more points in Group F until Ronaldo's late intervention.

"That's what happens at Old Trafford; we had to throw caution to the wind and got lucky in the end," said Solskjaer.

"When you've got Cristiano on the pitch, there is always a chance."

Ronaldo's late show beat Solskjaer's famous strike to win the Champions League in 1999 as United's latest winning goal in the competition.

However, for most of the 95 minutes, Villarreal were the better side and were left to rue not taking their chances, as they sit at the bottom of the group on one point from two games.

"We're annoyed. The game was basically over, we just needed to see it out and we didn't," said Villarreal defender Pau Torres. "We were impeccable before that. We took the lead, were creating chance and were better than Man United at Old Trafford."

United were without three of their first-choice back four with Harry Maguire, and Luke Shaw sidelined by injury, while Aaron Wan-Bissaka was suspended after being sent off in the 2-1 defeat to Young Boys on matchday one.