Manchester United's hat-trick hero Robin van Persie was carried off on a stretcher in the final minutes of their Champions League second leg against Olympiacos.
A summary of all the Champions League matches played across Europe on Tuesday
News of all that's transpired on and off the football field
Paris St Germain will play Borussia Dortmund and Barcelona were pitted against an unpredictable Napoli, while Chelsea were drawn against Bayern Munich. City, who will be at home in the second leg, have yet to beat the Spanish side with two draws and two defeats in their previous four meetings.
Manchester United kept their season alive by reaching the Champions League quarter-finals with a memorable victory over Olympiakos Piraeus on Wednesday, but under-pressure manager David Moyes was not getting too carried away.
Manchester United striker Robin van Persie will be sidelined for up to six weeks after spraining his knee in the midweek Champions League win over Olympiakos Piraeus, the club said on Friday.
Manchester United will be clutching at the final straw of a sobering season when they attempt to overturn a 2-0 deficit against Greek side Olympiakos and reach the quarter-finals of the Champions League on Wednesday.
It was an epic night of high drama, and Robin van Persie was at his lethal best. The Dutch striker came up with a stunning hat-trick to lift the pressure on David Moyes and gloom surrounding Manchester United.
Champions Bayern Munich eased past hosts Fortuna Duesseldorf 4-1 on Sunday with winger Kingsley Coman scoring twice, to go a point clear at the top of the Bundesliga.
Napoli suffered an agonising exit from the Champions League after beating Premier League leaders Arsenal 2-0 on Wednesday.
News of all that's transpired on and off the football field
Neymar finally showed the goalscoring touch he has been threatening with a hat-trick as Barcelona shrugged off their recent dip in form with a 6-1 win over Celtic at the Nou Camp on Wednesday to seal top spot in Champions League Group H.
Cristiano Ronaldo's hat-trick for Real Madrid illuminated an opening night goals bonanza as the leading contenders began the Champions League group stage with a bang on Tuesday.
A summary of Wednesday's group matches in the UEFA Champions League.
Liverpool raised the bar so high and enjoyed such a huge winning margin in claiming the English Premier League title last season it would be churlish to doubt their credentials for a repeat showing.
Ambitious Russian clubs and Spartak Moscow go in search of their first Champions League points this week as they attempt to improve their country's unimpressive record in the competition.
European champions Real Madrid will face former champions Liverpool, FC Basel and debutants Ludogorets of Bulgaria following the draw for the group stage of the Champions league on Thursday.
The Bavarians, who have won the last seven league titles in Germany, last lifted Europe's top club trophy in 2013.
Former European champions Celtic were helped by two own goals as they thumped Astana 5-0 at home and a late goal from Wissam Ben Yedder gave Sevilla a 2-1 win at Istanbul Basaksehir in torrential rain.
Images from football matches played across Europe over the weekend.
A summary of the results of the football matches played across Europe on Sunday
Valencia have agreed to appoint Ernesto Valverde to replace Mauricio Pellegrino as their new coach until the end of the season, the Spanish club said on Monday.
Arsenal defender Andre Santos will undergo ankle surgery this week and is expected to be sidelined for around three months, the Premier League club said on Monday.
After damaging losses to Dinamo Zagreb and Olympiakos Piraeus in their first two fixtures, the Gunners have to win to advance to the knock-out stages
A summary of Wednesday's matches in the UEFA Champions League.
Inter Milan midfielder Christian Eriksen scored his first goal for the club since last month's move from Tottenham Hotspur to set up a 2-0 win at Ludogorets Razgrad in their Europa League last 32, first leg on Thursday. Getafe pulled off a surprise 2-0 home win over last year's Champions League semi-finalists Ajax Amsterdam, while Manchester United were held 1-1 at Club Brugge in wet and windy conditions. Wolverhampton Wanderers' Diogo Jota scored a second successive hat-trick in the competition to lead his side to a 4-0 victory over Espanyol and Arsenal won 1-0 at Olympiakos Piraeus with a late Alexandre Lacazette goal.
Jose Mourinho suffered a nightmare homecoming as Porto, the club he led to the Champions League title in 2004, inflicted a 2-1 defeat on his woefully out-of-sorts Chelsea side in Group G on Tuesday.
Robin van Persie has emerged as the man to lead Arsenal out of their early-season funk and the Dutch striker will be a key figure in ensuring their rehabilitation continues in the Champions League at home to Olympiakos on Wednesday.
"Tomorrow we don't play six points against zero. We play at 7.45, at 0-0 with 90 minutes to go," he said.
Atletico Madrid must not let down their guard after Wednesday's thumping Champions League win at home to Malmo, coach Diego Simeone said.
Panathinaikos won the Greek title for the first time in six years by beating Iraklis 2-0 on Sunday.
Jose Mourinho's Chelsea turned from domestic whipping boys back to European stalwarts on Wednesday, beating his former club Porto 2-0 to top Champions League Group G.
Girondins Bordeaux survived a second-half scare to grab a 2-1 win over Olympiakos Piraeus on Wednesday and give France a second team in the Champions League quarter-finals.
Arsenal eased into the group stages of the Champions League on Wednesday by outclassing Celtic 3-1 to enter Thursday's draw where they will be joined by Fiorentina, VfB Stuttgart, Olympiakos and APOEL Nicosia.
Arsenal, VfB Stuttgart and Olympiakos Piraeus all scored 2-0 away wins in their final Champions League playoff matches on Tuesday to take a big stride towards the group stage before next week's second legs.
Holders Barcelona booked a Champions League last 16 berth with a 2-1 win at Dynamo Kiev on Wednesday and were joined by Group F rivals Inter Milan, who sealed their passage with a 2-0 home defeat of Rubin Kazan.
News of all that's transpired on and off the football field
Manchester United's big-money signing Marouane Fellaini faces several weeks on the sidelines after having an operation on his wrist.
Ajax, semi-finalists last season, came from behind to beat PAOK 3-2 for a 5-4 aggregate win over the Greeks while Red Star knocked out FC Copenhagen on penalties after a bizarre shootout involving 22 spot-kicks.
Jose Mourinho, sacked by Manchester United last season after his reign there turned sour, has been charm personified since swapping punditry for the Tottenham job.