MILAN, Dec 3 (Reuters) - AC Milan's pursuit of Serie A leaders Juventus suffered a major setback when they lost 2-1 at Chievo Verona on Saturday.
Kakha Kaladze gave Milan the lead at Verona's Bentegodi stadium midway through the first half, but goals by strikers Sergio Pellissier and Simone Tiribocchi earned Chievo an unexpected victory.
The result left Milan second in the standings with 31 points from 14 matches, five points behind Juventus who play third-placed Fiorentina on Sunday (kickoff 1400 GMT). Chievo climbed to fifth on 24 points.
Fourth-placed Inter Milan beat Ascoli 1-0 thanks to a free-kick in the 24th minute from their Brazilian striker Adriano.
Milan's defeat comes at the start of a vital week in which they face Germany's Schalke 04 in a decisive Champions League game on Tuesday before taking on Inter in the derby on December 11.
'We can't stop and think too much about this game,' said Milan coach Carlo Ancelotti, 'We have to prepare ourselves for the match against Schalke on Tuesday.
'But we certainly could have controlled our lead much better. Chievo were much more decisive and showed greater desire than we did.
'We suffered and didn't play very well for an hour of the game, we need to improve in terms of our character,' he added.
Milan's task was never going to be easy against a Chievo side that had suffered just two defeats this season and they lost captain Paolo Maldini, who went off at the break with a muscle injury.
Kaladze's goal seemed to have set them on the right track. The defender put the visitors ahead in the 22nd minute, poking home a loose ball after keeper Lorenzo Squizzi had parried his header from an Andrea Pirlo cross.
Milan wasted a chance to extend their advantage on the half hour when Kaladze delivered a perfect cross into the path of Andriy Shevchenko, only for the Ukrainian striker to scuff wide from two metres.
That miss proved costly. Chievo's enterprising and well-organised play reaped reward on the stroke of halftime when Davide Mandelli flicked the ball on for Pellissier to beat Dida from close range.
In the second half, Ancelotti sent on Filippo Inzaghi in place of Shevchenko and Kaka for Rui Costa in an attempt to grab the winner.
Instead, it was second-half substitute Tiribocchi who had the last word, playing a neat one-two with strike partner Victor Obinna before curling the ball round Dida.
Inter dominated possession at a freezing San Siro but found Ascoli's well-organised defence and hard-working midfield tough to break down.
Adriano wasted a great chance to open the scoring in the eighth minute when he fired straight at visiting keeper Fernando Coppolla from close range.
The Brazilian then had a header tipped over the bar and Dejan Stankovic fired just wide as Inter produced some flowing football midway through the first half.
Adriano provided the breakthrough in the 24th minute with a superb 20-metre free-kick which crashed in off the post but Roberto Mancini's side found it hard going after the break.
In the 64th minute, Adriano could have made it 2-0 but his poor shot was blocked and Argentine Esteban Cambiasso was unable to take advantage of the loose ball.
In injury time, Nigerian substitute Obafemi Martins fired wide after being set clear on goal to end a frustrating night for Inter but one which at least delivered three points ahead of the derby.