The 25-year-old playmaker replaced full-back Alvaro Arbeloa in the 81st minute of the Group I World Cup qualifier in Tbilisi and within five minutes had conjured the crucial assist for Roberto Soldado's winner in a laboured 1-0 success.
Receiving the ball on the right of the penalty area, he waited for Soldado to peel away from his marker and struck a low cross that the Valencia striker turned into the net to finally end Georgia's stubborn resistance.
Coach Vicente del Bosque praised Fabregas for his "movement and intelligence" after the Georgia game, Spain's opener in a group which also includes France, Belarus and Finland.
"We had various options to try to break through the opposition defence... and in the end the gap opened up," Del Bosque said at a news conference.
"It wasn't about getting nervous but having patience and playing in the most orthodox way possible because otherwise we would have exposed ourselves to the counterattack, with the obvious danger that carries with it."
Under Guardiola's replacement, Tito Vilanova, he has yet to make much of an impression this term and was an unused substitute in last month's Spanish Super Cup defeat to arch rivals Real Madrid.
He fluffed two clear chances in Barca's 1-0 La Liga win at home to Valencia this month but has a chance to redeem himself on Saturday when the leaders seek a fourth win in four games at Madrid-based side Getafe.
