There was almost the worst possible start for the hosts, because within 40 seconds Cristante and Gianluca Mancini both hesitated, allowing Chris Bedia to burst in and fire wide from 13 yards.

Miroslav Stevanovic also saw his shot deflected inches wide off Cristante’s shin, but Roma broke through with their first real scoring opportunity.

Andrea Belotti broke away from his marker down the right and allowed Zeki Celik to roll across for Lukaku, whose finish took a deflection off Keigo Tsunemoto to loop over a helpless goalkeeper.

After taking the lead, Roma seemed fairly content to let Servette hold long periods of possession without creating any real danger.

Instead, Belotti pulled back from the by-line for Lukaku, this time the decisive Nicolas Vouilloz deflection took it over the bar.

Within 30 seconds of the restart it was 2-0, as substitute Lorenzo Pellegrini and then Lukaku nodded on a Stephan El Shaarawy cross, allowing Belotti to spring the offside trap and pounce.

They added a third in style when El Shaarawy’s cross found Celik on the other end, he knocked it back in with his header for Pellegrini to volley home with the inside of the boot.

However, Pellegrini’s match lasted barely 11 minutes when he limped off with yet another muscular issue.

Belotti completed his brace with the lowest of diving headers on a Leandro Paredes corner from seven yards.

Roma made the most of the situation to give some of their youth players a run-out, including the debut for Francesco D’Alessio.