Match ends, Chelsea 3, Roma 3.
Eden Hazard rescued Chelsea's unbeaten start to the Champions League group stage after a dominant Roma had fought back from two goals down to lead in a pulsating game at Stamford Bridge.
Hazard scored in each half, heading in to level from Pedro's cross with 15 minutes to go to keep the Blues top of Group C.
The Belgium forward had given Chelsea a two-goal lead in the first half after David Luiz scored a wonderful opener.
But the Serie A side fought back, with Aleksandar Kolarov scoring before Edin Dzeko netted twice in six minutes.
- Follow the reaction to Wednesday's Champions League games
- Mourinho must look at himself, not Chelsea - Conte
The striker's first was a sensational volley, and Dzeko then combined with fellow former Manchester City man Kolarov to head in and put the visitors in front.
That lead lasted just five minutes as Hazard levelled to keep Chelsea's two-point lead intact, with Atletico Madrid held to a goalless draw by FK Qarabag in the other Group C game.
Hazard saves stuttering Chelsea
Chelsea boss Antonio Conte knows what it takes to win the Champions League, having done so as a player with Juventus in 1995-96, though the trophy has so far eluded the Italian as a manager.
But Conte has warned the Blues hierarchy his squad is stretched, despite spending nearly £180m in the summer, with the English champions suffering successive defeats in the Premier League to Manchester City and bottom-placed Crystal Palace.
Chelsea were nearly staring at a third loss in a row in all competitions for the first time since 2006, as Roma outclassed the hosts with a high-pressing game that saw the Italians dominate possession and make nearly 200 more passes than their English counterparts.
It was the first time a Conte side has conceded three goals in a Champions League game, and it could have been more as Dzeko headed wide late on following his superb double.
But, ultimately, Chelsea remain top of the group after three games, as they again dug out a result - having scored a 94th-minute winner against Atletico Madrid last time out in Europe.
Conte has Hazard to thank for that, with the Belgian first putting the Blues into a two-goal lead with a smart finish from a deflected Alvaro Morata shot and then guiding a header beyond goalkeeper Alisson after Roma's fantastic response.
Premier League old boys haunt Conte
Bosnia-Herzegovina forward Dzeko never scored against Chelsea during his five seasons at Manchester City in the Premier League.
The 31-year-old responded to that on Wednesday with what may be one of the goals of the Champions League, watching former Tottenham defender Federico Fazio's long pass drop over his shoulder before lashing a left-footed volley past Thibaut Courtois.
That was the goal that brought Roma level, after former Manchester City left-back Kolarov eased his way into the box and sent a deflected effort into the roof of the net.
Dzeko has been in superb form for Roma this season, and the striker added his 10th goal of the campaign when he met Kolarov's free-kick inside the area to head in unmarked and briefly give Roma the lead.
It was the sort of poor defending that characterised the game on both sides, and will worry Conte heading into Saturday's game against fourth-placed Watford.
The David Luiz experiment
Asked why he was starting Luiz in midfield before the match, Conte's response of "I only have two midfielders" offered little insight into his side's tactical makeup, but it was clear the eccentric Brazilian was there to do a job normally perfected by the injured N'Golo Kante.
Luiz may be a defender by trade, but the Brazil international took his goal with all the finesse of a 30-goal-a-season striker.
But for all his boundless energy, an over-eager Luiz conceded more fouls than any other player during his 55 minutes on the pitch, giving an already dominant Roma an easy way out of pressurised situations.
Both he and Tiemoue Bakayoko struggled to deal with Roma's runs from deep and, despite also claiming Luiz had a calf problem, Conte said it was a tactical decision to bring the Brazilian off for Pedro in the second half.
Conte said Bakayoko was another to suffer a knock during the game, leaving the Italian limited options in midfield with Chelsea facing a run of five games in the next 16 days.
Man of the match - Aleksandar Kolarov (Roma)
'We suffered in possession' - Conte
Chelsea boss Antonio Conte: "It was fair. It was a difficult game against a good team. Above all in the first half we suffered, our performance was good but for sure our football is different than today.
"We suffered in possession and it wasn't easy in the first half, despite scoring two goals. The change of the system wasn't good, but when you are in a difficult situation you have to change and sometimes to improvise.
"When we changed in the second half the situation was changing. David Luiz had a little problem in his calf and in this moment I can't risk my players, we are playing always the same players."
Hazard's first in Europe for 952 days - the stats
- Roma have never won an away game against English opposition in the Champions League (drew three, lost six).
- Eden Hazard scored his first Champions League goals since 11 March, 2015 vs PSG - 952 days ago.
- Hazard's two goals were more than he had managed in his previous 14 games in all competitions for Chelsea (one).
- Chelsea have scored four goals from outside the box in the Champions League this season, more than any other team.
- Roma have failed to keep a clean sheet in their last 23 away games in the Champions League.
- Edin Dzeko made his 100th appearance for Roma in all competitions and has netted 59 goals so far.
Fifth-placed Chelsea host fourth-placed Watford on Saturday (12:30 BST), before Everton visit Stamford Bridge in the Carabao Cup next Wednesday (19:45).
Roma, meanwhile, visit Torino in Serie A on Sunday (14:00).
- 21ZappacostaSubstituted forRüdigerat 77'minutes
- 30David LuizSubstituted forPedroat 57'minutes
- 14BakayokoBooked at 69mins
- 10E HazardSubstituted forWillianat 80'minutes
- 25da Silva Peres
- 5Nunes Jesus
- 6StrootmanSubstituted forFlorenziat 83'minutes
- 30Santos da SilvaSubstituted forPellegriniat 74'minutes
- 8PerottiSubstituted forEl Shaarawyat 88'minutes
- 16De Rossi
- 92El Shaarawy
- Damir Skomina
- Shots on Target
Second Half ends, Chelsea 3, Roma 3.
Attempt missed. Gary Cahill (Chelsea) header from the centre of the box is just a bit too high. Assisted by Cesc Fàbregas with a cross following a set piece situation.
Foul by Radja Nainggolan (Roma).
Willian (Chelsea) wins a free kick on the right wing.
Foul by Lorenzo Pellegrini (Roma).
Pedro (Chelsea) wins a free kick in the attacking half.
Substitution, Roma. Stephan El Shaarawy replaces Diego Perotti.
Attempt blocked. Álvaro Morata (Chelsea) header from the centre of the box is blocked. Assisted by Antonio Rüdiger with a cross.
Attempt missed. Antonio Rüdiger (Chelsea) header from the centre of the box is high and wide to the left. Assisted by Cesc Fàbregas with a cross following a corner.
Corner, Chelsea. Conceded by Maxime Gonalons.
Substitution, Roma. Alessandro Florenzi replaces Kevin Strootman.
Attempt missed. Edin Dzeko (Roma) header from very close range is close, but misses to the right. Assisted by Bruno Peres with a cross.
Substitution, Chelsea. Willian replaces Eden Hazard.
Substitution, Chelsea. Antonio Rüdiger replaces Davide Zappacosta.
Attempt missed. Radja Nainggolan (Roma) left footed shot from outside the box misses to the left. Assisted by Lorenzo Pellegrini.
Goal! Chelsea 3, Roma 3. Eden Hazard (Chelsea) header from the centre of the box to the bottom left corner. Assisted by Pedro with a cross.
Substitution, Roma. Lorenzo Pellegrini replaces Gerson.
Goal! Chelsea 2, Roma 3. Edin Dzeko (Roma) header from the centre of the box to the bottom right corner. Assisted by Aleksandar Kolarov with a cross following a set piece situation.
Tiemoué Bakayoko (Chelsea) is shown the yellow card for a bad foul.