Barcelona slumped to a rare loss on Wednesday, while Manchester United and Chelsea each needed late goals to win in a wild night of Champions League action.
Barcelona wereunbeaten in 12 consecutive matches in all competitions before falling 2-1 at Celtic, who are now just two points behind the Spanish giants with two group matches remaining.
Meanwhile, United came back from a goal down to beat Braga 3-1 and qualify for the second round in a match that was stopped briefly because of a floodlight outage. Advancing with two matches to spare marked a sharp turnaround from last season, when United failed to make it to the knockout round.
Elsewhere, defending champions Chelsea needed a header from Victor Moses four minutes into injury time to win 3-2 over Shakhtar Donetsk.
Also, last season’s runner-up, Bayern Munich, thrashed Lille 6-1 and Italian champions Juventus also dominated in a 4-0 win over Danish side Nordsjaelland.
In other matches, Galatasaray won their first away match in the competition in 10 years by beating CFR Cluj 3-1 with a hat-trick from Burat Yilmaz; midfielder Sofiane Feghouli scored twice to help Valencia beat BATE Borisov 4-2 and take the lead in Group F; and substitute Oscar Cardozo scored two second-half goals to give Benfica a 2-0 win over Spartak Moscow.