El Shaarawy at the double as Roma thump Chelsea
The rematch in Rome's Stadio Olympico after a 3-3 thriller in London two weeks ago did not disappoint the 55,000 crowd in Rome as Chelsea coach Antonio Conte was frustrated on his return to Italy.
El Shaarawy rifled in two first half goals -- the first after less than a minute and the second nine minutes before the break -- with Argentine Diego Perotti adding a third on 63 minutes.
A second win in four games moves the Romans closer to the last-16, thwarting Chelsea who had been hoping to seal a spot in the knockout rounds with two games to go.
Eusebio Di Francesco's side now have eight points from four games, one point ahead of Chelsea, with Atletico Madrid third on three points after being held 1-1 by Qarabag.
Conte's Chelsea were a shadow of the team that played at Stamford Bridge earlier this month.
French midfielder N'Golo Kante, who has just returned from a hamstring injury, was left out by Conte, along with Nigerian Victor Moses as Greek defender Kostas Manolas started on the bench for Roma.
El Shaarawy and Perotti backed up Edin Dzeko in the Roma attack with Chelsea counting on the trident of Eden Hazard, Alvaro Morato and Pedro.
After an opening burst the hosts were ahead after just 38 seconds when Dzeko nodded down and El Shaarawy blasted into the back of the net past a stunned Thibaut Courtois.
Hazard -- who scored a brace in the first leg along with Dzeko -- was omnipresent early for Chelsea with Alisson saving twice at the near post, Alvaro Morata also missing an opportunity in front of goal for the English champions.
But after going close a second time, El Shaarawy broke through again on 36 minutes following a long ball from Radja Nainggolan.
A Tiemoue Bakayoko header looked dangerous but Alisson dived to clear four minutes before the break.
Perotti got the third after the break following a Cesc FabregasÂ error in midfield to pile the pressure on Chelsea, who could thank Belgian keeper Courtois for pulling off some key saves including a searing Manolas header.
And Argentine Perotti could have made it 4-0 minutes later as unmarked he fired over an empty net.
Fabregas came off midway through the second half with Danny Drinkwater getting his Champions League debut.
But it was all Roma, as Nainggolan was kept out by Courtois, along with a Dzeko header from the resulting corner.
It was the third straight defeat for Chelsea in Italy, with their last win back in 2003 over Lazio.
Roma next travel to Atletico Madrid with Chelsea facing the long trip to Qarabag in Azerbaijan.