Manchester United took a huge stride towards the Champions League knockout stages on Wednesday, seeing off an uninspired Benfica 1-0 to make it three wins out of three thanks to a goalkeeping howler.
Marcus Rashford broke the deadlock midway through the second half when an inswinging free-kick from the left was carried over his line by teenage goalkeeper Mile Svilar.
Results
GROUP A
Benfica 0-1 Manchester United
CSKA Moscow 0-2 FC Basel
GROUP B
Bayern Munich 3-0 Celtic
RSC Anderlecht 0-4 Paris Saint Germain
GROUP C
FK Qarabag 0-0 Atletico Madrid
Chelsea 3-3 Roma
GROUP D
Barcelona 3-1 Olympiakos
Juventus 2-1 Sporting Lisbon
Svilar, who became the youngest goalkeeper to start a Champions League game aged just 18 years and 52 days, caught the ball but in doing so stepped backwards over his line to gift United the lead.
It was a lucky break for the Premier League high-flyers, who, despite dominating possession, had been struggling to create meaningful chances against the Portuguese champions, twice winners of the European Cup.
Rashford limped off with about 15 minutes to go, replaced by Anthony Martial, who tested Svilar early following an incisive run into the box.
United, who did not qualify for the Champions League last season, now have nine points out of nine in Group A and look almost certain to qualify for the knockout stages but Benfica, without a single point, have a mountain to climb.
At Barcelona, meanwhile, Lionel Messi scored his 100th goal in European competition to lead 10-man Barcelona to a 3-1 victory at home to Olympiakos.
Messi hit the century mark in 122 European matches when he curled a free kick over the wall in the 61st minute. Goalkeeper Silvio Proto got a hand on the ball but couldn't keep it out as Messi took his career tally in the Champions League to 97 goals.
After Barcelona had gone ahead thanks to an own goal by Dimitris Nikolaou in the 18th minute, the hosts were left a man down three minutes before halftime. Gerard Pique got a second booking for using his arm to steer the ball into the net. The strike was disallowed.
However, Barcelona continued to outclass Olympiakos despite playing with 10 men.
Messi drew a foul from Nikolaou near the edge of the area to set up his free kick. Messi's strike gave him 18 goals in 17 matches for Barcelona and Argentina side this season.
Barcelona's star provided the pass for left back Lucas Digne to score in the 64th when he dribbled around a defender before cutting the ball back through the area for the defender to drive it home.
Barca made it three wins from as many matches in Group D and extended their unbeaten run at home in the competition to 23 straight games.
At Stamford Bridge, Eden Hazard came to the rescue of erratic Chelsea after his side blew a two-goal lead, winding up in a dramatic 3-3 draw with Roma.
Antonio Conte's team looked on course for a comfortable victory thanks to first-half goals from David Luiz and Hazard.
But Roma's Aleksandar Kolarov struck before halftime to spark a stirring fightback from the Serie A side.
Former Manchester City forward Edin Dzeko bagged a brace after the interval to give Roma the lead, only for Hazard to spare Chelsea's blushes with a late leveller.
Chelsea remain two points clear of Roma at the top of Group C, but this was the latest in a growing list of alarming displays from the Premier League champions.
Blues boss Antonio Conte reportedly held a lengthy inquest with his squad in the aftermath of Saturday's shock 2-1 loss at Crystal Palace and this erratic performance -- which extended their winless run to three matches -- may well spark another dressing down from the Italian.
In Brussels, Paris Saint-Germain needed less than three minutes to stamp their authority against Anderlecht and coasted to a 4-0 victory over the Belgian champion.
Kylian Mbappe scored on a balmy night with a drive from a tight angle early on before setting up Edinson Cavani for a tap-in header in the 44th minute.
And after halftime, the world's most expensive player, Neymar, also had his moment - sending a low free kick under the soaring defenders and past goalkeeper Matz Sels in the 66th. Angel Di Maria closed out the scoring in the 88th.
It left PSG with 12 goals for and none against and three victories atop Group B with 9 points.
Bayern Munich has six points, Celtic three and Anderlecht none.