MILAN (AP) -- Inter Milan's crisis deepened on Sunday after crashing to its seventh loss in eight matches, going down 1-0 to Napoli in Serie A from Ezequiel Lavezzi's second-half goal.
Lavezzi, who scored twice in Napoli's 3-1 win over Chelsea in the first leg of the Champions League in midweek, pounced in the 59th minute to help his team rise to fifth place in the standings.
Napoli defender Salvatore Aronica was sent off in the 78th minute for committing a serious foul. Giampaolo Pazzini missed a glorious chance to snatch a draw for Inter three minutes from time.
Elsewhere, Lazio beat Fiorentina 1-0.
Inter, whioch has now not scored in five successive games, barely had a sight of goal and Napoli deservedly went in front just before the hour mark. Blerim Dzemaili did well to keep hold of the ball and dribble downfield before passing to Lavezzi, whose shot went into the far right corner for his fourth goal in three games.
Inter should have leveled when Yuto Nagatomo picked out an unmarked Pazzini in the middle of the area but his header went wide.
"Why should I take a step backwards? I won't resign because I believe in this squad," Inter coach Claudio Ranieri said. "We have the desire and the energy to return to winning ways.
"We need to return to scoring goals and winning. Napoli played well and it was a good game. It's a pity Pazzini missed."
Lazio had also been in the middle of a bad run, having lost four of its past five games. The side has had a troubled past few days after coach Edy Reja offered his resignation on Thursday following his team's exit from the Europa League at the hands of Atletico Madrid.
Former Chelsea great Gianfranco Zola seemed to be on verge of taking over on Saturday after having talks with the club in Rome, but Reja was eventually convinced to stay following clear-the-air talks with Lazio president Claudio Lotito.
Klose beat the offside trap to score what was to prove the winner in the 36th minute. Fiorentina looked to have equalized eight minutes after the break but Alessio Cerci's goal was ruled out for offside.
In the other evening game, Udinese beat Bologna 3-1 to remain level on points with third-place Lazio.
The league's top scorer, Antonio Di Natale, gave Udinese the lead from the spot in the 38th minute after he had been tripped by Diego Perez just inside the box.
Dusan Basta and Antonio Floro Flores secured victory, either side of Panagiotis Kone's strike for Bologna.
Earlier in the day, German Denis scored a hat trick as struggling Atalanta stunned nine-man Roma 4-1. Roma was without suspended Francesco Totti and coach Luis Enrique left Daniele De Rossi out of his squad as punishment after the midfielder turned up late to a meeting.
Guido Marilungo put Atalanta ahead in the 10th minute before Denis scored his first goal in the 19th. Roma gave itself hope when Fabio Borini pulled one back shortly afterwards.
However, Denis struck again two minutes after the interval and Pablo Osvaldo was dismissed for an off-the-ball incident. Denis grabbed his third in the 66th as the Argentine took his season tally to 15.
Visitors Roma had another man sent off eight minutes from time when Marco Cassetti saw red for dissent.
Siena beat Palermo by the same scoreline. Palermo defender Federico Balzaretti was sent off with less than two minutes on the clock for bringing down Mattia Destro when he was clean through on goal, but it took the lead when Igor Budan headed in Fabrizio Miccoli's corner.
Siena leveled after being granted a soft penalty when Matias Aguirregaray was adjudged to have fouled Franco Brienza. Claudio Terzi converted the resulting spot kick.
Goals from Erjon Bogdani, Luca Rossettini and Brienza, from a free kick, gave Siena victory.
Lecce has now lost only one of its past eight matches after beating Cagliari 2-1. Luis Muriel and Andrea Bertolacci scored for Lecce, either side of Joaquin Larrivey's equalizer from the spot.
Cagliari defender Michele Canini was sent off for a second yellow card offense.
Fellow struggler Novara's run of four games without defeat came crashing to an end in losing 3-1 at Catania.
Gonzalo Bergessio pounced on the half-hour mark before Giovanni Marchese and Alejandro Gomez sealed the result early in the second half. Raffaele Rubino grabbed a consolation for Novara, which remains a point above Cesena following its 1-0 loss at Chievo Verona.
Davide Moscardelli scored late on for Chievo after Cesena defender Maurizio Lauro had been dismissed for a second yellow at the start of the second half.