ROME, January 23- Udinese ended Leonardo's perfect record since taking over as Inter Milan coach with a 3-1 win over the Italian champions on Sunday while city rivals Milan retained their four-point lead at the top.
Inter, aiming for a sixth straight win since the Brazilian’s arrival in the San Siro dugout, took the lead after quarter of an hour through Dejan Stankovic.
Udinese then stunned Inter with goals from Cristian Zapata and Antonio Di Natale – his 15th of the season – to go into the break 2-1 up, with Maurizio Domizzi adding a third midway through the second half.
Inter remain in fifth place on 35 points but are nine adrift of leaders AC Milan who edged Cesena 2-0 in Sunday’s late game.
But it wasn’t a convincing Milan performance as they needed an own-goal from Maximiliano Pellegrino for a 45th-minute opener.
Pellegrino, who had also netted against his own team last weekend in the clash with Roma, was put under pressure from Antonio Cassano and Zlatan Ibrahimovic and was unable to prevent the ball crossing the line.
Ibrahimovic added the second goal in the third minute of injury time for his 13th league strike of the season.
Milan’s win was overshadowed by a serious shoulder injury suffered by veteran defender Alessandro Nesta who was hurt in a collision with Igor Budin and was substituted in the 20th minute.
He could be ruled out for up to three weeks after it was originally thought he’d miss three months.
"It was a deserved win," said Milan coach Massimiliano Allegri. "We had lots of chances, so I am satisfied. But we have worries over Gennaro Gattuso who has a thigh injury and Alessandro Nesta also with his shoulder."
Giving his reaction to his first loss in charge Leonardo told Inter’s official website that the team would get over the loss to Udinese.
"In football you lose games; it’s no big deal. It won’t change the way we see things and it won’t change the way I see the team."
"We got off to a great start," he added.
"Taking the lead at a stadium like this and against a team like Udinese was no mean feat, so I don’t think it was a case of us making mistakes or losing our concentration.
"Perhaps we were a bit tense because of how a few things went. The first half was an evenly balanced affair but Udinese had the upper hand in the second half.
"However, I must say that hardly any of the goals we’ve conceded from set pieces have been because we were caught out by the opposition; most have been because of a lucky deflection or rebound. So I don’t think we have a problem with man-marking at set pieces."
For Udinese, it was their first win over Inter in 14 attempts.
Napoli replaced Roma in second place after a 2-0 win at Bari.
Argentina’s Ezequiel Lavezzi fired Napoli in front with a 38th-minute free-kick before Uruguayan striker Edinson Cavani added the second, three minutes from time with his 14th goal of the season.
Lazio stayed in fourth place after crashing to a shock 3-1 defeat at Bologna.
Sergio Floccari gave Lazio a fifth-minute lead before Uruguayan Gaston Ramirez levelled in the 36th minute.
Three minutes later Marco Di Vaio put Bologna ahead and the same player added the third in stoppage time for his 13th league goal of the campaign.
Juventus are sixth, just behind Inter on goal difference, after a 0-0 draw at Sampdoria where their only fit striker Amauri played with a face mask to protect a broken nose.
On Saturday, Roma stayed in the title hunt with a 3-0 win over Cagliari.