Olympiakos conceded a goal after just 69 seconds of their Champions League campaign and went on to lose 3-2 to Sporting Lisbon at home in Group D on Tuesday.
Manchester United eased back into Champions League life as Marouane Fellaini, Romelu Lukaku and Marcus Rashford put Basle to the sword.
Barcelona and Juventus will renew their recent rivalry when they meet at the Camp Nou in the group stage of the UEFA Champions League on Tuesday.
Real Madrid's Cristiano Ronaldo was named UEFA's Player of the Year, beating Lionel Messi and Gianluigi Buffon to the prize.
Champions League holders Real Madrid will face Borussia Dortmund and Tottenham in a difficult group following the draw ceremony in Monaco on Thursday.
The 32 teams in this season's Champions League group stage can now begin to think about their dream draw after the final seeding pots were confirmed following Wednesday's final qualifying ties.
Liverpool scored three times in a devastating opening 21 minutes as they reached the Champions League group stage with a 6-3 aggregate win over Bundesliga side Hoffenheim at Anfield.
Celtic progressed into the Champions League group stage as expected with an 8-4 aggregate win over Astana, but they were made to sweat in their 4-3 second-leg defeat in Kazakhstan.
Second-half goals from Jose Callejon and Lorenzo Insigne earned Napoli a 2-0 win in Nice and ensured their qualification for the Champions League group stages.
Goals from Dries Mertens and Jorginho were enough to earn Napoli a 2-0 win against Nice in their Champions League qualifying play-off first leg.
Celtic put one foot into the Champions League group stages with a 5-0 thumping of Astana in the first leg of their playoff at Parkhead.
Trent Alexander-Arnold scored his first Liverpool goal as Jurgen Klopp's side took a 2-1 lead in their Champions League qualifier against Hoffenheim.
With a new season in the champions league on the horizon, a lot of people are already putting together their predictions for exactly what is going to happen.
Manchester United were outclassed at times as Real Madrid won the UEFA Super Cup to give Jose Mourinho food for thought at the start of his second season in the hot seat.
Liverpool will have to overcome Hoffenheim in a two-legged playoff to reach the group stages of the Champions League.
James Forrest's second-half strike gave Celtic a 1-0 win over Rosenborg and took the Hoops another step closer towards Champions League football.
Ajax failed to make it through to the Champions League qualifiers for the third consecutive year on Wednesday when they were eliminated on the away goals rule 3-3 on aggregate after a 2-2 home draw against Ligue 1 side Nice.
Mario Balotelli's first-half goal was only enough for Nice to earn a 1-1 draw against Ajax in the first leg of their Champions League third qualifying round match on Wednesday.
Olympiakos opened their Champions League campaign with a 3-1 win away to Partizan Belgrade in the third qualifying round on Tuesday.
Juventus goalkeeper Gianluigi Buffon said he was hugely disappointed after his side crumbled in the second half to lose 4-1 to Real Madrid in the Champions League final.
Real Madrid coach Zinedine Zidane accepted that his team had "made history" by beating Juventus 4-1 in Saturday night's final in Cardiff to become the first team to retain the Champions League title in its modern, expanded format.
Juventus boss Massimiliano Allegri says his side "let go psychologically" in the second half of their 4-1 Champions League final defeat to Real Madrid in Cardiff on Saturday.
Cristiano Ronaldo's brace ensured Real Madrid became the first team in history to win back-to-back Champions Leagues with a 4-1 victory over 10-man Juventus.
Real Madrid coach Zinedine Zidane says his players feel no extra pressure as they aim to make history with back-to-back Champions League titles in Saturday's final against Juventus.
Juventus coach Massimiliano Allegri says his side "must" win the Champions League on Saturday night, insisting that now is their time.
The brilliance of Karim Benzema and Isco booked Real Madrid a place back in the UEFA Champions League final after the holders survived an early scare in a 2-1 second-leg loss to city rivals Atletico at the Vicente Calderon.
Juventus coach Max Allegri believes his side "have a very good chance of winning the Champions League" after beating Monaco on Tuesday to reach the final.
Juventus reached their second Champions League final in three seasons after a 2-1 win at home to Monaco on Tuesday night secured a 4-1 victory on aggregate.
Gonzalo Higuain scored twice from Dani Alves passes to put Juventus in control of their Champions League semifinal with Monaco ahead of next week's second leg in Turin.
Cristiano Ronaldo scored a hat trick in his second straight Champions League game as Real Madrid swept aside city rivals Atletico 3-0 at the Bernabeu in the first leg of their semifinal on Tuesday night.
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.
Liverpool will face Roma in the semifinals of the Champions League later this month as they continue their attempt to win it for the first time since 2005.
Cristiano Ronaldo scored an injury-time penalty to book Real Madrid's place in the Champions League semifinals after losing the second leg 3-1, but winning the tie 4-3 on aggregate.
Bayern Munich are through to the Champions League semifinals for the seventh time in nine years after a 0-0 draw in their quarterfinal second leg with Sevilla.
Barcelona suffered a shock Champions League defeat at the hands of Roma, losing 3-0 in their quarterfinal second leg at the Stadio Olimpico to go out 4-4 on aggregate thanks to an away goal for the Serie A side in the first leg.
Mohamed Salah and Roberto Firmino scored second-half goals as Liverpool won 2-1 at Manchester City to reach the Champions League semifinals 5-1 on aggregate.
A pair of own goals helped Barcelona take a major step toward the Champions League semifinals with a 4-1 win over Roma at the Camp Nou on Wednesday.
Liverpool drew significant first blood in their all-English Champions League quarterfinal as Manchester City were blown away in 45 minutes in a raucous 3-0 Anfield defeat.
Bayern Munich fought back from a goal down to beat Sevilla 2-1 in their Champions League quarterfinal first leg on Tuesday night at the Ramon Sanchez Pizjuan.
Cristiano Ronaldo scored a spectacular brace to hand Real Madrid a 3-0 victory over Juventus in their Champions League quarterfinal first leg on Tuesday.
Liverpool face Manchester City in an all-English Champions League quarterfinal after the draw in Switzerland on Friday.
Two goals from Lionel Messi -- one the fastest of his career and the other his 100th in the Champions League -- helped Barcelona beat Chelsea 3-0 at the Camp Nou and advance to the quarterfinals 4-1 on aggregate.
Bayern Munich coasted into the quarterfinals of the Champions League with a 3-1 win over Besiktas in Istanbul to complete an 8-1 aggregate win.
A second-half strike from Edin Dzeko sent Roma into the quarterfinals of the Champions League with a 1-0 home victory against 10-man Shakhtar Donetsk.
Sevilla are through to the Champions League quarterfinals after beating Manchester United 2-1 in their second leg at Old Trafford on Tuesday night.
Manchester City slipped to their first home defeat since December 2016 as Basel won the second leg of their Champions League last-16 tie 2-1.
Two goals in under three second-half minutes saw Juventus come back from 1-0 down to knock Tottenham Hotspur out of the Champions League, with a 2-1 win at Wembley putting them through to the quarterfinals 4-3 on aggregate.
Liverpool eased into the quarterfinals of the Champions League for the first time in nine years with no great alarm in a lifeless goalless draw at home to Porto.
Holders Real Madrid eased into the Champions League quarterfinals with a 2-1 win at 10-man Paris Saint-Germain.
David De Gea's exceptional display saved Manchester United's blushes as Jose Mourinho's men somehow escaped with a goalless draw from a match dominated by Sevilla.
Shakhtar Donetsk pulled off a second-half comeback to beat Roma 2-1 in their Champions League round-of-16 first leg in Ukraine on Wednesday night.
Bayern Munich look assured of a Champions League quarterfinal spot for a seventh straight season after thrashing 10-man Besiktas 5-0 in Germany.
Lionel Messi broke his goal duck against Chelsea to deny Antonio Conte's side a crucial lead over Barcelona in their Champions League showdown.
Sadio Mane scored a hat trick and Mohamed Salah continued his phenomenal run with a 30th goal of the season as Liverpool won 5-0 at Porto to virtually assure themselves a Champions League quarterfinal place.
Cristiano Ronaldo scored twice and Marcelo got another as Real Madrid came from a goal down to take a 3-1 lead over Paris Saint-Germain in the first leg of their Champions League clash at the Bernabeu.
Ilkay Gundogan scored twice as Manchester City put one foot in the Champions League quarterfinals with an emphatic 4-0 win over Basel.
Christian Eriksen completed a remarkable Tottenham comeback as they rallied from two down to draw with Juventus in the Champions League last 16.
Cristiano Ronaldo scored from a free kick to help Real Madrid beat Gremio 1-0 and claim the Club World Cup in Saturday's final in Abu Dhabi.
Gareth Bale was the surprise hero as Real Madrid survived a shock against outsiders Al Jazira to win 2-1 in Wednesday's extra dramatic Club World Cup semifinal in Abu Dhabi.