Paulo Dybala picked out Lukaku with a clever cross as the Belgium striker headed Roma in front in the fifth minute at the Stadio Olimpico.
Bruno Fernandes and Ricardo Horta netted the goals for Roberto Martinez's Portugal, with Cristiano Ronaldo not on the scoresheet, to end with 10 wins from 10 matches in Group J.
Lukaku grabbed his third goal in five league games for Roma after latching onto a clever pass from Paulo Dybala midway through the first half.
Belgium forward Lukaku rolled in Roma's sixth in the 82nd minute of a dominating performance in which talisman Paulo Dybala also got off the mark for the season with a brace.
Romelu Lukaku completed his season-long loan move to Roma from Chelsea on Wednesday after being welcomed as a hero by supporters.
According to the Italian sports daily, Roma will pay the London club 5.8 million euros ($6.2 million) and the player will receive an annual salary of 7.5 million euros
The visitors had been rocked by a row between new coach Domenico Tedesco and veteran goalkeeper Thibaut Courtois in the build-up to the game, and made a slow start before Lukaku pounced with two close-range finishes towards the end of the first half
Thierry Henry said that it will be difficult for Romelu Lukaku to handle after he made some crucial mistakes in Inter's Champions League final loss against Manchester City.
Lukaku, on loan at Inter from Chelsea, has struggled with injuries and form this season, but has scored three goals in his last three games
Paulo Dybala picked out Lukaku with a clever cross as the Belgium striker headed Roma in front in the fifth minute at the Stadio Olimpico.
Bruno Fernandes and Ricardo Horta netted the goals for Roberto Martinez's Portugal, with Cristiano Ronaldo not on the scoresheet, to end with 10 wins from 10 matches in Group J.
Lukaku grabbed his third goal in five league games for Roma after latching onto a clever pass from Paulo Dybala midway through the first half.
Belgium forward Lukaku rolled in Roma's sixth in the 82nd minute of a dominating performance in which talisman Paulo Dybala also got off the mark for the season with a brace.
Romelu Lukaku completed his season-long loan move to Roma from Chelsea on Wednesday after being welcomed as a hero by supporters.
According to the Italian sports daily, Roma will pay the London club 5.8 million euros ($6.2 million) and the player will receive an annual salary of 7.5 million euros
The visitors had been rocked by a row between new coach Domenico Tedesco and veteran goalkeeper Thibaut Courtois in the build-up to the game, and made a slow start before Lukaku pounced with two close-range finishes towards the end of the first half
Thierry Henry said that it will be difficult for Romelu Lukaku to handle after he made some crucial mistakes in Inter's Champions League final loss against Manchester City.
Lukaku, on loan at Inter from Chelsea, has struggled with injuries and form this season, but has scored three goals in his last three games
A Romelu Lukaku brace on his 30th birthday, a further strike from Lautaro Martinez and an unfortunate Ruan Tressoldi own goal were enough for Inter to claim a seventh straight win in all competitions and move level on 66 points with second-placed Juventus