Eden Hazard and Willian hit the woodwork as Chelsea were held to a goalless draw at Dynamo Kiev.
Bayer Leverkusen and Roma battled out a 4-4 draw in a thrilling Champions League Group E clash in Germany that saw both sides produce remarkable comebacks.
Zenit St Petersburg are on the brink of qualifying for the knockout stages of the Champions League after defeating Lyon 3-1 in Russia.
Vincent Aboubakar netted his seventh goal of the season as Porto beat Maccabi Tel-Aviv 2-0 to climb to the top of Champions League Group G.
Ideye Brown struck the decisive goal for Olympiakos at the Maksimir Stadium to send Dinamo Zagreb spinning to a second Group F Champions League defeat.
Stefan Mitrovic's own goal allowed Valencia to take a big step towards qualification from Champions League Group H as Gent were beaten 2-1 at the Mestalla.
Juan Mata was the star of the show as Manchester United got off the mark in the Champions League with a narrow 2-1 win over Wolfsburg.
Cristiano Ronaldo's double took him past 500 career goals and handed Real Madrid a narrow 2-0 Champions League victory over 10-man Malmo.
Sergio Aguero struck a last-gasp penalty winner as Manchester City came from behind to ignite their Champions League campaign with a 2-1 win at Borussia Monchengladbach.
Juventus may be struggling in Serie A but it is a different story in the Champions League with the Italian giants clinching the second win in as many games on Wednesday with a home triumph over Sevilla.
Zlatan Ibrahimovic was frustrated in his attempts to overhaul Paris St Germain's all-time goalscoring record as a late strike was officially recorded as an own goal.
Benfica came from a goal behind to beat Atletico Madrid 2-1 at the Vicente Calderon and go top of Group C.
Jose Mourinho's return to former club Porto ended in a 2-1 Champions League defeat as Chelsea's miserable start to the season continued.
Stand-in goalkeeper David Ospina had a night to forget as Arsenal slumped to a 3-2 home defeat against Olympiakos on Wednesday to leave their Champions League hopes in jeopardy.
Late goals from Sergi Roberto and Luis Suarez saved Barcelona's blushes and earned them a valuable win over visitors Bayer Leverkusen in Champions League Group E.
Robert Lewandowski's incredible goal scoring form continued as the striker's hat trick helped Bayern Munich thrash Dinamo Zagreb 5-0.
Belarusian champions BATE Borisov shocked Italian side Roma with a 3-2 win at the Borisov-Arena in Champions League Group E.
Valencia got their Champions League campaign up and running with a 1-0 victory at Lyon in Group H.
Oleg Shatov's second-half goal earned Zenit St Petersburg a 2-1 Champions League victory over Gent at the Petrovsky Stadium on Tuesday night to strengthen their position at the top of Group H.
Goals from Andriy Yarmolenko and Aluisio Junior Moraes gave Dynamo Kiev a 2-0 Champions League victory over Maccabi Tel-Aviv in Group G.
Champions League holders Barcelona saw their perfect start to the season ended after they were held to a 1-1 draw by Roma at the Stadio Olimpico in Wednesday's Group E opener.
Diego Costa scored his first Champions League goal for Chelsea as the beleaguered Premier League champions claimed a much-needed fillip by thrashing Maccabi Tel Aviv at Stamford Bridge.
Arsenal had striker Olivier Giroud sent off as they slumped to a disappointing 2-1 defeat in their Champions League Group F opener at Dinamo Zagreb.
Thomas Muller's scoring streak continued as he netted a brace to steer Bayern Munich to a 3-0 win at Olympiakos in their Champions League Group F opener.
Hakan Calhanoglu scored a brace either side of Javier Hernandez's first goal for Bayer Leverkusen as the German side made a winning start in Champions League Group E by seeing off BATE Borisov 4-1 at home.
Zenit St Petersburg got their Champions League campaign off to a winning start as they recorded a 3-2 victory at Valencia in Wednesday's Group H opener.
Gent fought back to clinch a point in a heroic display after having two men sent off in their first ever Champions League group match which ended 1-1 against Lyon.
Luke Shaw suffered a horrific suspected broken leg as Manchester United's return to the Champions League ended in a disappointing 2-1 defeat to PSV Eindhoven.
Manchester City suffered familiar European wobbles as they surrendered a lead to lose their Champions League Group D opener 2-1 to Juventus.
Cristiano Ronaldo hit a second-half hat trick as Real Madrid opened their Champions League campaign with a 4-0 victory over 10-man Shakhtar Donetsk in Tuesday's Group A showdown at the Santiago Bernabeu.
Cristiano Ronaldo's Champions League debut for Juventus lasted only 29 minutes as he was red-carded but the Italians began their Group H campaign impressively with a 2-0 victory at Valencia on Wednesday.
Paul Pogba scored two first-half goals as Manchester United spoiled Young Boys' first appearance in the group stage of the Champions League by cruising to a comfortable 3-0 victory at the Stade de Suisse on Wednesday.
Manchester City looked far from potential Champions League winners as they fell to a surprise 2-1 loss at home to Olympique Lyonnais on Wednesday with a flat performance that leaves them with plenty of work to do to progress from Group F.
CSKA Moscow salvaged a 2-2 draw with Viktoria Plzen in the Champions League on Wednesday after a penalty deep in stoppage time.
Bayern Munich midfielder Renato Sanches had a goal and an assist in his return to Benfica in a 2-0 victory on Wednesday.
Real Madrid rode goals from Isco and Gareth Bale to a 3-0 win against Roma in their Champions League Group G opener at the Camp Nou on Wednesday.
The youngest coach in Champions League history drew his debut game Wednesday as Hoffenheim's match at Shakhtar Donetsk finished 2-2.
Nicolas Tagliafico scored two second-half goals as Ajax marked their return to the Champions League group stages with a 3-0 victory over AEK Athens on Wednesday.
A stoppage-time goal from Roberto Firmino gave Liverpool a 3-2 win over Paris Saint-Germain on a dramatic Champions League night at Anfield.
Red Star Belgrade ground out a 0-0 home draw against Napoli on the Serbian side's Champions League debut as their goalkeeper Milan Borjan made a flurry of telling saves in a pulsating Group C clash on Tuesday.
Borussia Dortmund's United States forward Christian Pulisic came off the bench to grab a late goal for a 1-0 Champions League Group A victory over Club Brugge on Tuesday.
Atletico Madrid battled their way back from a goal down to pull off a confidence-boosting 2-1 win at AS Monaco in Champions League Group A on Tuesday, with a defiant response to their troubling start to the domestic season.
Inter Milan scored two late goals as they came from 1-0 down to beat Tottenham Hotspur 2-1 in a dramatic Champions League clash at the San Siro.
Lionel Messi scored a record-setting hat trick as Barcelona opened their Champions League campaign in Group B with an impressive 4-0 win against PSV Eindhoven at the Camp Nou.
Juventus will face Manchester United in the Champions League group stage this season, giving Cristiano Ronaldo a chance to play against his former team.
A thrilling draw away to Salzburg enabled Serbian champions Red Star Belgrade to reach the Champions League group stage for the first time where they will be joined by Portugal's Benfica and Dutch side PSV Eindhoven.
Four-time European champion Ajax qualified for the Champions League group stage on Tuesday for the first time in four years, while AEK Athens and Young Boys Bern ended even longer absences.
Former European Cup winners Ajax Amsterdam stayed firmly on course to reach the Champions League group stage after a dazzling first half helped them to a 3-1 home win over Dynamo Kiev.
Former European Cup winners PSV Eindhoven fought back to grind out a 3-2 win at BATE Borisov on Tuesday in their Champions League playoff round first-leg clash while Benfica were held to a 1-1 home draw by PAOK.
Atletico Madrid finally got their own back on Real Madrid in European competition by snatching a 4-2 win over their city rivals after extra time to lift the UEFA Super Cup on Wednesday.
AEK Athens and PAOK Thessaloniki gave Greek football fans plenty to cheer about as both clubs reached the Champions League playoff round and joined three former winners of Europe's elite club competition on Tuesday.
Odsonne Edouard scored a brace to help Celtic to a 3-1 victory in the first-leg of their Champions League second round qualifying tie with Rosenborg in Glasgow.
Liverpool boss Jurgen Klopp believes Mo Salah is likely to miss the World Cup after leaving the Champions League final injured in the first half.
Gareth Bale said he wants to be playing every week -- which "has not happened this season" -- after leading Real Madrid to the Champions League trophy in Saturday's 3-1 win over Liverpool.
Cristiano Ronaldo cast doubt over his future with Real Madrid after they won the Champions League for the third consecutive season on Saturday in a 3-1 win over Liverpool.
Real Madrid beat Liverpool 3-1 to win the Champions League for a third successive season thanks to a spectacular two-goal substitute appearance from Gareth Bale and a performance to forget for Loris Karius.
Liverpool set up a repeat of their 1981 meeting against Real Madrid despite a first Champions League defeat of the season at the Stadio Olimpico.
Two goals from Karim Benzema helped Real Madrid advance to their third straight Champions League final 4-3 on aggregate after a scintillating 2-2 draw with Bayern Munich in the second leg of their last-four clash on Tuesday.
Real Madrid will be firm favourites to reach another Champions League final after winning 2-1 away to Bayern Munich in the first leg of their semifinal.
Liverpool scored five but conceded two late goals as Roma gave themselves a glimmer of hope in a 5-2 defeat at Anfield after the home side had swept into a huge lead.