Holders Real Madrid were drawn against Borussia Dortmund, Sporting Lisbon and Legia Warsaw on Thursday in the group stage of football's Champions League, while Barcelona will face Manchester City and Bayern Munich will reencounter old foes Atletico Madrid.
The draw took place in Monaco and was carried out by former stars Clarence Seedorf, Roberto Carlos, Ian Rush, Thierry Henry and Ruud van Nistelrooy.
Real idol Cristiano Ronaldo - who scored the winning penalty in The Whites' final triumph last season against neighbours Atletico - will this time face Sporting Lisbon, the team where he began his illustrious career.
Ronaldo, 31, started out at Sporting in 2002 then moved to Manchester United after just one promising season at the Lisbon club.
"It will be very special for me to play against Sporting," Ronaldo said.
"Sporting have a special place in my heart because that is where it all started for me."
Ronaldo was Thursday named Europe best player by UEFA, for having guided Real to triumph for a record 11th time last season - and for having captained Portugal to unexpected success at Euro 2016.
Sporting Lisbon and Legia Warsaw should give Real few problems, though Dortmund will certainly be a tough proposition.
The Whites were eliminated by Dortmund at the semi-final stage in 2013, but took revenge a year later by beating the Germans in the quarter-finals.
"There was a lot of anticipation in our camp ahead of the draw. We now have an appealing group," Dortmund coach Thomas Tuchel said.
"It's difficult but equally attractive. Matches against Real are becoming classics for Dortmund. We are looking forward to meeting the holders."
The draw also brings coach Pep Guardiola back to Barcelona, where he won so much, with his new-look Manchester City side.
Guardiola coached Barcelona to Champions success in 2009 and 2011, but will have his work cut out now to control the Spanish champions given the good form of South Americans Lionel Messi, Luis Suarez and Neymar - who guided Barca to another Champions triumph in 2015.
The Barca-City group seems to be the much-feared 'Group of Death', since the other members are former European heavyweights Borussia Moenchengladbach and Celtic, both of whom qualified this week through the play-offs.
"It is not a nightmare draw because we are in a wonderful competition - but it is a very tough group. We always seem to get Barca, but better now than later I suppose," City's director of football Txiki Begiristain said.
"Pep (Guardiola) knows the group very well - obviously Barcelona but also Borussia Moenchengladbach from his time in Germany."
Playing for Moenchengladbach will be Catalan defender Marc Bartra, who was sent packing by Barca coach Luis Enrique in June after two years of mutual misunderstanding between the two.
Meanwhile, German champions Bayern Munich - whom Guardiola left for City in June - will again face Atletico Madrid, the team that ousted them in the semi-finals last season.
Bayern dramatically beat Atletico in the 1974 final but Atletico took long-awaited revenge on them in the semis in April.
"Bayern are a very good team but so are we," Atletico midfielder Koke said.
"We had two very tough games against them last season, and I am sure these next two matches with them will be just as hard."
PSV Eindhoven and debutants Rostov are the other sides in that group.
Arsenal have been drawn with Paris St Germain, Basel and Ludogorets, while Napoli are in with Benfica, Dynamo Kiev and Besiktas.
Tottenham will face CSKA Moscow, Monaco and Bayer Leverkusen, while suprise Premier League champions Leicester have been given a relatively benign draw in the shape of Porto, Brugge and Copenhagen.
Meanwhile, 2015 finalists Juventus will face Europa League winners Sevilla, Lyon and Dynamo Zagreb.
Juventus midfielder Sami Khedira said: "This is going to be very interesting. The draw has brought us trips to Spain, France and Croatia. I can't wait for the tournament to start."
And Sevilla keeper Sergio Rico said: "We have been draw into a rather strong group, I think.
"Last season, we did badly in the group stage (and had to go into the Europa League, which Sevilla won). We really hope to do better this time, and we will try our best to prosper in the group."
The group stage begins September 13 and 14 and continues to December 6 and 7. The final will be held in Cardiff's Millennium Stadium on June 3.