Esteban Cambiasso inspired a stirring fightback as Inter Milan struck twice in the last 18 minutes to record a 2-1 victory on Thursday and hand Fiorentina their first Serie A defeat of the season.
The Argentine midfielder, back to his best after struggling last season, cancelled out Giuseppe Rossi's second-half penalty before Brazilian fullback Jonathan grabbed the winner with seven minutes to go.
Both unbeaten teams went into the match with 10 points from four games and Fiorentina delivered the first blow when Italy forward Rossi converted a penalty on the hour after Joaquin was tripped.
It was the fifth league goal of the season for Serie A's joint top scorer who is back in action after suffering successive knee injuries which sidelined him for the best part of two years.
Fiorentina, who had looked dangerous throughout the first half, sat back on their lead and gifted Inter a goal from a corner in the 72nd minute.
Goalkeeper Neto flapped at the ball and his team mates missed another chance to clear before Cambiasso, 33, acrobatically hooked in the equaliser.
Fiorentina seemed more likely to grab the winner until Ricky Alvarez's cross found Jonathan at the far post and he eluded Matias Fernandez's weak challenge to smash the ball into the roof of the net.
Inter, vastly improved under new coach Walter Mazzarri, are now level with Juventus and Napoli on 13 points, two behind leaders AS Roma who have a 100 percent record.
Image: Esteban Cambiasso of Inter Milan celebrates scoring the first goal against Fiorentina at Giuseppe Meazza Stadium in Milan on Thursday
Photograph: Claudio Villa/Getty Images