Didier Drogba hobbled off in the first half as Chelsea wrapped up the game with a 2-1 victory over Ferencvaros in Hungary, with Fabregas' magnificent play.
Drogba just rejoined the club following his departure from Galatasaray this summer. The athlete took a knock just half an hour into the Blues' final European friendly and was pulled out and replaced by Oscar.
Former West Brom forward Zoltan Gera put the hosts ahead just before half-time before Ramires levelled with a wonder-strike from distance.
The half-time substitute Fabregas, who just signed from Barcelona in June, was able to lead the team to success on 81 minutes with a splendid solo goal.
The club youngsters Kurt Zouma and Andreas Christensen joined forces at center-back in a first eleven that also included new left-back from Atletico Madrid Filipe Luis.
Andre Schurrle and Drogba both went close for Jose Mourinho's side before the Ivorian was forced off after Gera's opener.
Schurrle's astounding free-kick that missed by a few inches was Chelsea's best chance of the first half, but they remained behind and so Mourinho brought on Branislav Ivanovic, Gary Cahill, Mohamed Salah, Fabregas and Diego Costa at the break.
But Fabregas - who had an outstanding second half - produced a moment of pure class, breaking through midfield and firing in, with shades of Frank Lampard, to win the game late on.