Bayern Munich began their defence of the Champions League title in ominous fashion by crushing Atletico Madrid 4-0 on Wednesday, while Liverpool and Manchester City also won but Real Madrid suffered a shock defeat.
Madrid, the record 13-time European champions, went down to a 3-2 home loss against Shakhtar Donetsk, showing how far Zinedine Zidane's side are just now from the standards being set by Bayern.
Two months after scoring the winner in the final against Paris Saint-Germain in Lisbon, Kingsley Coman put Bayern ahead against Atletico in Group A and later scored a stunning individual effort to wrap up the victory at an empty Allianz Arena.
In between Leon Goretzka and Corentin Tolisso were also on target for the German champions, with the latter's strike a stunner from long-range.
"The winning goal in last season's final is a good motivator, but it's in the past now and we have fresh goals this season," Coman told Sky Sports.
It was Bayern's 12th consecutive Champions League win while the result for Atletico equalled their worst defeat under Diego Simeone.
Bayern next go to Russia to play Lokomotiv Moscow, who battled back to draw 2-2 at Red Bull Salzburg on Wednesday.
Eder put Lokomotiv ahead in Austria, only for Dominik Szoboszlai to crash in a brilliant equaliser.
A deflected Zlatko Junuzovic goal put the hosts in front, but Vitali Lisakovich headed in to earn the Russian side a point.
Real were 3-0 down at half-time against Shakhtar at the Alfredo di Stefano stadium and fell short with a second-half fightback to get their European campaign off to a disastrous start.
A depleted Shakhtar were without 10 first-team players and nine members of staff due to coronavirus infections and had seven starters aged 21 or under.
Strikes from Tete and Manor Solomon, either side of a Raphael Varane own-goal, gave the Ukrainian champions a three-goal half-time lead.
Luka Modric and Vinicius Junior pulled goals back and Fede Valverde thought he had grabbed an injury-time equaliser but his deflected shot was ruled out for an offside.
Missing the injured Sergio Ramos, Real have now won just one of their last seven Champions League home games. This was also a second defeat in five days as they prepare to go to Barcelona for the Clasico on Saturday.
"We lacked a bit of everything, but above all our confidence, which is the most important thing," said Zidane.
Real are already up against it in Group B, even if rivals Inter Milan and Borussia Moenchengladbach cancelled each other out in a 2-2 draw at San Siro.
Romelu Lukaku scored twice for Inter, opening the scoring early in the second half and then turning in a late equaliser.
In between Ramy Bensebaini netted a penalty for Gladbach and Jonas Hofmann scored what he thought was a late winner.
Liverpool shook off the absence of Virgil van Dijk to edge Ajax 1-0 behind closed doors in Amsterdam in Group D.
Van Dijk is set to miss the rest of the season with a knee injury but Jurgen Klopp's side kept a clean sheet and took all three points after Nicolas Tagliafico turned a wayward Sadio Mane shot into his own net on 35 minutes.
"It was not sunshine football but we wanted three points and we got it," said Klopp.
The 2019 European champions will hope to build on this result when they host Midtjylland next week.
The Danes were outclassed at home by Atalanta on Wednesday, losing 4-0 with Duvan Zapata, Alejandro "Papu" Gomez and Luis Muriel scoring in the first half and debutant Aleksei Miranchuk adding a late fourth.
Pep Guardiola's City made it three wins for English clubs this midweek as they came from behind at home to beat Porto 3-1.
Luis Diaz gave Porto the lead with a superb individual goal but Sergio Aguero's penalty soon brought City level and Ilkay Gundogan's free-kick put them ahead on 65 minutes.
Substitute Ferran Torres then scored a superb goal to make sure of the win.
Also in Group C, Egyptian substitute Ahmed Hassan headed in a stoppage-time winner as Olympiakos downed Marseille 1-0.
Paris, France | AFP