Several European giants suffered setbacks in the Champions League. Bayern Munich were held to a dramatic 3-3 draw by Norwegian side Viking after conceding a late equaliser. Manchester United lost 2-0 away to Atletico Madrid, while Inter Milan were beaten 4-3 by Club Brugge. Villarreal also came from behind to defeat Napoli 3-1.

Viking Hold Bayern to Dramatic Draw

Viking 3-3 Bayern Munich

Viking made a flying start against Bayern, taking the lead in the opening minute when Stensnes headed home from a corner.

The Norwegian side doubled their advantage in the 38th minute through Christiansen, leaving Bayern with plenty of work to do after the break.

Bayern responded strongly in the second half. Harry Kane pulled one back from the penalty spot in the 53rd minute before heading in his second goal just three minutes later from a Kimmich cross.

Luis Diaz then completed Bayern's comeback in the 71st minute, putting the visitors 3-2 ahead.

However, Bayern's hopes of securing victory suffered another blow when Michael Olise was sent off in the 74th minute. Viking took advantage and Hauge headed home in the 90th minute to make it 3-3.

Bayern were therefore forced to settle for a point after throwing away their lead late in the match.

Atletico Madrid Beat 10-Man Manchester United

Atletico Madrid 2-0 Manchester United

Atletico Madrid needed just 47 seconds to break the deadlock, with Pablo Barrios putting the hosts ahead almost immediately after kick-off.

United managed to stay within touching distance for much of the match, but Atletico gradually took greater control after the break.

Manchester United's task became even harder when Leny Yoro was shown a red card late in the game. Atletico capitalised on their numerical advantage, with substitute Ademola Lookman scoring from close range to seal a 2-0 victory.

Tresoldi Hat-Trick Sends Club Brugge Past Inter

Inter Milan 3-4 Club Brugge

Club Brugge produced one of the biggest results of the night by beating Inter Milan 4-3 at San Siro in a thrilling seven-goal contest.

Nicolo Tresoldi opened the scoring from the penalty spot in the 30th minute before Lautaro Martinez equalised for Inter shortly before half-time.

Tresoldi then took over the game after the break, scoring in the 63rd and 74th minutes to complete his hat-trick.

Martinez pulled another goal back for Inter in the 81st minute, but Club Brugge restored their advantage through Vermant four minutes from the end.

Bonny scored for Inter in the third minute of stoppage time, but it was not enough to prevent Club Brugge from securing a memorable 4-3 victory.

Villarreal Come From Behind to Beat Napoli

Villarreal 3-1 Napoli

Napoli made a strong start away from home, taking the lead inside the opening 10 minutes through Amir Rrahmani.

Villarreal responded before half-time. Georges Mikautadze equalised in the 23rd minute before Mourino put the hosts ahead with a superb long-range strike just three minutes later.

Napoli pushed for an equaliser after the break but could not find a way through. Villarreal eventually sealed the win in the 86th minute when Oluwaseyi found the net.

The victory ended Villarreal's 13-match winless run in the Champions League. Napoli, meanwhile, have now lost both of their opening matches.

Villarreal will next travel to face Liverpool, while Napoli will take on Bodo/Glimt.