A first-half brace from Roma striker Stephan El Shaarawy enabled the Giallorossi to a memorable 3-0 win over Premier League champions Chelsea in their UEFA Champions League Group C game at the Stadio Olimpico.

The last time the two sides met, they shared six goals between them in a thrilling 3-3 draw at Stamford Bridge but the return leg on Wednesday was all about one side — Roma.

Shaarawy, playing on the right in Roma’s front-three that includes Edin Dzeko and Diego Perotti, rocked the hosts with a wondrous half-volley in the first minute itself.

Chelsea, under pressure to clinch three points in Italy after making a middling start to their Premier League title defence, tried to respond immediately via star man Eden Hazard, but the winger’s shot from an acute angle was too weak to beat Roma keeper Alisson.

The game was witnessing end-to-end action and Hazard would come close to finding an equaliser but his shot went straight to Alisson, who gathered with ease. Hazard continued to probe the Roma defence but the Blues’ best chance fell to striker and club record-signing Alvaro Morata.

Fullback Aleksandar Kolarov was closed down on the wing by Pedro and the ricochet fell Morata’s way but the Spaniard lacked the composure to finish and sent his effort high into the stands.

Roma, on the other end, went close via Shaarawy again but Thibaut Courtois made a key save with his legs.

However, it was Shaarawy who would double their advantage nine minutes before the interval.

While his first goal was sheer brilliance, the second had an element of luck in it as well. Radja Nainggolan’s speculative punt bounced in front of Chelsea defender Antonio Rudiger but the German inexplicably let the ball bounce past him and Shaarawy pounced to guide it past Courtois.

Chelsea had a chance to pull one back via Tiemoue Bakayoko, but the Frenchman couldn’t guide his header on target from a Cesc Fabregas corner.

The two Blues midfielders, playing together in the absence of N’Golo Kante, were just not on top of their game and the likes of Nainggollan, Danielle De Rossi and Kevin Strootman had the better of them.

At half-time, Roma were cruising with a 2-0 lead and Chelsea’s Italian manager Antonio Conte knew he needed to make a drastic change if they were to leave his homeland with even a point.

Conte replaced winger Willian with centre-back Gary Cahill in the 56th minute. However, the move didn’t have the desired effect as minutes after the Brazilian’s introduction, Roma further extended their lead as wide-man Perotti cut in from the left and sent in a fierce, low shot at the first-post that beat Courtois in the 63rd minute.

As Chelsea threw caution to the winds after going down 3-0, Roma countered and ideally should have added a fourth goal when Dzeko spun and played Perotti through. Three Blues defenders were focused on the Bosnian striker who showed presence of mind to lay it off for his teammate, but Perotti’s finish was high, much to the relief of the visitors.

Roma continued to dominate proceedings despite leading by a comfortable margin and Nainggolan tested Courtois from distance. The Belgian shot-stopper made a remarkable stop late in the second-half from a close-range header to prevent the Giallorossi from extending their lead.

With the win, Roma take top spot in Group C as they have eight points from four games while Chelsea slip to second with a points tally of seven.

Elsewhere in Group C, Atletico Madrid were held to a 1-1 draw by Qarabag FK and the Rojiblancos remain in third place with three points.

Chelsea still have a strong chance of progressing to the knockout stages, but their loss in Italy has derailed their chances of emerging as group-winners and they will have to hope Roma slip in their final two games.