Davide Zappacosta scored a spectacular goal and Michy Batshuayi netted twice as Chelsea equaled their biggest Champions League win with a thrashing of competition debutants Qarabag.
The Blues – making their return to European competition having failed to qualify last season – rested several first-team players for the visit of the Azerbaijani champions, but still won with ease.
Pedro opened the scoring with a 20-yard curler from Willian’s lay-off.
Italy right-back Zappacosta, on his first Blues start, ran 50 yards down the right wing, before sending over a cross that flew past Ibrahim Sehic.
Cesar Azpilicueta headed home a third after the break from Cesc Fabregas’ cross.
Willian hit the crossbar, and substitute Tiemoue Bakayoko scored his first Blues goal with a deflected shot from close range.
Batshuayi then scored twice in the final 15 minutes – firing in from outside the box after being picked out in space by Bakayoko and then scrambling home Zappacosta’s cross.
The win was always likely to be the easiest game in the group, with Roma and Atletico Madrid the other two teams in Group C. Those sides drew 0-0 in Rome’s Olympic Stadium.
Chelsea boss Antonio Conte – whose side face seven games in 21 days – was able to name striker Alvaro Morata, Bakayoko and three of the back five who beat Leicester at the weekend on the bench. Captain Gary Cahill returned after a three-match domestic ban but was largely untested – although he was booked for a reckless foul.
Arguably the biggest winner of the changes was Zappacosta, a deadline-day signing from Torino for a reported £23m, who scored on his full debut.
He admitted afterwards that the goal was not intentional, but it still capped off a good performance and Victor Moses will have cause to worry about getting his place back.
With the game sealed, Eden Hazard, yet to start this season for the Blues after an ankle injury, was given 32 minutes to boost his match fitness before Sunday’s game against Arsenal.
Batshuayi will be happy to score his first two goals of the season, although the standard of opposition – and his overall performance – are unlikely to have overly concerned the rested Morata.
