Ten-man Genoa held Internazionale to a goalless draw at the San Siro on Sunday to earn their first point on the road this season and stall Inter's recent revival.
A lively Genoa dominated the first half and went close to scoring on two occasions, but a red card to midfielder Ivan Juric allowed the home side to take control.
Despite their efforts, the Nerazzurri came up against a brick wall of determined Genoa defenders who more than deserved a point for their efforts.
Inter coach Jose Mourinho paid his compliments to Genoa on the eve of the game and he would have been further impressed with his opponents from the bench.
The Rossoblu dominated the first half, showing no fear against the defending champions after a brief period of containment.
Inter had the first chance of the game when Zlatan Ibrahimovic was caught off guard when the ball reached him at the far post and he was unable to direct his header goalward.
But the rest of the half belonged to the visitors.
The first moment of danger in front of Julio Cesar's goal came when Giuseppe Sculli headed across goal to Marco Rossi, who failed with his acrobatic effort, but was adjudged offside anyway.
Diego Milito should have done better with his header from eight yards from Sculli's cross minutes later.
But it was Giandomenico Mesto who missed the best chance of the half.
The Genoa winger was free in front of an open goal after Milito's shot was only parried by Julio Cesar, but he blazed his shot wide.
He proved he is capable of better minutes later when he unleashed a 25-yard pile-driver which cannoned back off the underside of the crossbar with Julio Cesar beaten.
Mourinho was clearly not happy with what he had seen from his side and he made two changes during the break to form a four-man attack with Victor Obinna and Mario Balotelli coming on.
He added Julio Cruz in an all-out assault, and things swung in Inter's favor when Genoa were reduced to 10 men as Juric was shown a second yellow card.
While the visitors had more than matched their rivals with 11 men, playing half an hour with only 10 changed the complexion of the match.
Giuseppe Biava deflected a shot against his own crossbar with Balotelli unable to convert the rebound as Inter stepped up their search for a goal.
All the home side were able to do was send cross after cross into the arms of Genoa goalkeeper Rubinho and, for the first time this season, they failed to score at the San Siro and lost their place at the top of Serie A as a result.
