Stephan El Shaarawy struck twice, including the fastest goal of this season's Champions League after just 39 seconds, to help thrust AS Roma to the top of their Champions League group with a convincing 3-0 win over lacklustre Chelsea on Tuesday.
Home advantage counts for Roma
Following the sides' thrilling 3-3 draw in London two weeks earlier, the Italian international striker's brace was the highlight of another impressive display from Roma which allowed them to leapfrog the English champions at the summit of Group C.
El Shaarawy's thunderous first-minute shot was the earliest recorded in any match in the competition this term and, despite Chelsea creating early chances, Antonio Rudiger's defensive indecision allowed him to nip in for a neatly-taken second after 36 minutes.
Not for the first time this season, Chelsea again looked uncharacteristically disorganised at the back as Diego Perotti thrashed home a third after 63 minutes to move Roma on to eight points, one clear of Chelsea, who slip to second.
After the thrilling fare between the two sides at Stamford Bridge, the one-sided nature of the return, which saw Chelsea suffer their biggest defeat under Antonio Conte since their 3-0 loss at Arsenal last season, was a sign of unsettled times for the Italian.
Yet it took no time for the duel to explode into life again.
Hazard and Morata give hope for Chelsea reply
When Aleksandar Kolarov's hoofed ball from the left flank was nodded back a mite fortuitously by Edin Dzeko in Roma's opening foray, El Shaarawy was on to the loose ball in a flash to send his right-footed shot on the half-volley crashing past Thibaut Courtois.
Chelsea countered brightly with Eden Hazard causing problems for the home rearguard, Alvaro Morata hooking one shot over from close range and Tiemoue Bakayoko heading just wide.
Yet when the former Roma man Rudiger had a lapse of concentration at the back, allowing El Shaarawy to pounce on a speculative ball forward from Radja Nainggolan and nudge his effort expertly past Courtois, Chelsea's poise disintegrated.
Second half Roman dominance
Most shocking for Conte was just how tamely his side capitulated after the break, looking nothing like the team which looked so solid throughout their Premier League title-winning campaign.
Cesc Fabregas, in his 100th Champions League match, typified the malaise by giving the ball away to kick start the move that saw Perotti strike a fierce 25-metre shot past Courtois.
The Argentine should then have made it four but ballooned his shot high and Courtois had to make two fine saves in a minute, including a dazzling stop at point blank range from substitute Kostas Manolas, to spare Chelsea further indignity.
The Premier League side's only consolation after their nightmarish Halloween performance was that they were still effectively in control of their destiny after Atletico Madrid's surprise draw with Qarabag.