Frank Lampard and Romelu Lukaku were on target as Chelsea came from behind to beat Roma 2-1 in Washington DC.
Erik Lamela had fired the Italian club ahead midway through the first half at the RFK Stadium, following an error by Mark Schwarzer.
Manager Jose Mourinho made six half-time substitutions, two of whom scored.
Lampard levelled matters on the hour while Lukaku snatched a deflected winner in the closing moments.
With the game still goalless, Michael Essien was denied by Roma keeper Morgan De Sanctis early on before Roma opened the scoring.
After Schwarzer had failed to deal with Ryan Bertrand's back-pass, Lamela tapped home from close range after the ball had hit a post.
Schwarzer prevented Roma from making it two-nil, diving low to his right to keep out Pablo Osvaldo's drive.
At the other end De Sanctis produced another good save from a John Terry header.
Eden Hazard and Demba Ba combined to set up Lampard who fired home the equaliser with a low 20-yard strike.
De Sanctis blocked Ramires before Chelsea's teenage substitute keeper Jamal Blackman saved from Osvaldo.
But with time running out, Hazard and Ba were once again influential as Chelsea found the back of the net for a second time through Lukaku.