(Reuters) - Both coaches were sent off as leaders Juventus scrambled a 1-0 win at bottom club Catania on Sunday with a performance which was anything but polished.
AC Milan ended a four-match losing run by holding Lazio 1-1 in a meeting of the league's two crisis clubs and Inter Milan hit the woodwork four times before going down 2-1 to a late goal at home to Atalanta.
Fourth-placed Fiorentina boosted their hopes of a Champions League spot with a 1-0 win at third-placed Napoli who had Faouzi Ghoulam sent off for a foul on Marko Bakic in the 37th minute.
Udinese beat relegation-threatened Sassuolo 1-0 after both teams missed penalties and Sampdoria responded to last week's stinging criticism from coach Sinisa Mihajlovic by thrashing Verona 5-0.
Carlos Tevez's 16th goal of the season kept Juventus 14 points clear at the top and on course for a third successive title under coach Antonio Conte.
The champions have 78 points from 29 games while Roma, 2-0 winners at Chievo on Saturday, are on 64 with a game in hand. They are followed by Napoli (58), in the Champions League playoff sport, and Fiorentina (51).
Conte and his opposite number Rolando Maran were ordered from the touchline simultaneously in the first half for dissent as the match threatened to boil over.
"I think the referee wanted to send a signal to the players by sending off the coaches and trying to calm things down," Conte told Sky Sport Italia.
"It was basically a warning, as he couldn't send the players off that early."
There was little sign of the gulf between the two sides and Catania looked capable of a shock win until Tevez scored with a shot which slipped through Mariano Andujar's hands just before the hour.
Catania striker Gonzalo Bergessio, who had been involved in several exchanges with opponents, was sent off for elbowing Giorgio Chiellini eight minutes later.
Milan coach Clarence Seedorf, reportedly given two matches to sort out his team's problems or face the sack, dropped maverick striker Mario Balotelli at Lazio.
The hosts had problems of their own as their fans continued a boycott in protest at the administration of club president Claudio Lotito, leaving the Stadio Olimpico largely empty.
Milan went ahead just before halftime when Kaka's cross-shot was deflected off Abdoulay Konko and wrong-footed goalkeeper Etrit Berisha at the near post.
Alvaro Gonzalez headed Lazio level on the hour and Balotelli, brought on early in the second half, struck the post with eight minutes left.
Former Spain forward Joaquin Sanchez scored an 87th minute winner for Fiorentina, heading Manuel Pasqual's cross into an empty net with three minutes to play after Napoli goalkeeper Pepe Reina was caught out of position.
"We were still better than Fiorentina with 10 men," said Napoli coach Rafael Benitez.
Giacomo Bonaventura scored twice, the second with a 90th- minute header which slipped through goalkeeper Samir Handanovic's legs, to give Atlanta a shock 2-1 win at Inter.
Inter, who replied through Mauro Icardi, dominated the second half as Guarin smashed a long-range effort against the crossbar and Rodrigo Palacio sent a header against the foot of the post.
That was followed by an incredible double miss in the 85th minute when Jonathan's shot rebounded off the bar to Icardi whose point-blank range effort was blocked by a defender and struck the post.
Inter were left joint fifth on 47 points with Parma who drew 1-1 at home to Genoa.
Sampdoria, beaten 3-0 at Atalanta last week, bounced back to demolish Verona with Roberto Soriano scoring twice and Gianluca Sansone, Renan and Angelo Palombo sharing the other goals. Renan's effort came after a corner was deflected into his path by the referee.
Antonio Di Natale, making a club record 324th Serie A appearance for Udinese, celebrated by putting them ahead in the 26th minute but blotted his performance by firing wide from the penalty spot 10 minutes later.
Sergio Floccari sent a second-half penalty against the post for Sassuolo who were left floundering in the relegation zone.
(Reporting By Brian Homewood, editing by Josh Reich)