Four off at Bologna as own goal rescues Inter
Pescara coach Giovanni Stroppa, in charge for only 13 games, became the fifth coaching victim of the season after his side missed a penalty and had two players dismissed in a 1-0 defeat to fellow strugglers Siena.
Four players were sent off, three of them from Palermo, and two penalties were awarded as hosts Bologna beat the Sicilian side 3-0.
Second-placed Inter Milan were rescued by a late own goal from Davide Astori as they drew 2-2 at home to Cagliari but were furious after having a stoppage-time penalty appeal turned down and had coach Andrea Stramaccioni sent off for dissent.
The club declared a media silence, apart from president Massimo Moratti who gave an angry television interview to the Mediaset Premium television channel from his car as he left San Siro.
"I can say that for three games in a row, we have had to deal with refereeing injustices, which have prevented us from getting the result," he said.
Two goals from Alberto Aquilani helped Fiorentina thrash Atalanta 4-1 in Florence to go third. Gonzalo Rodriguez and Luca Toni also scored as the hosts, a far cry from last season's struggling outfit, chalked up their fifth win in a row.
Parma twice came from behind to draw 2-2 at Udinese where 35-year-old Antonio Di Natale opened the scoring for the hosts with his eighth goal of the season.
Defending champions Juventus, held 0-0 at home by Lazio on Saturday, lead with 32 points from 13 games. Inter are four points behind with Fiorentina and Napoli, who drew 2-2 with AC Milan on Saturday, a further point adrift.
Sampdoria quickly took control of the derby when Andrea Poli turned in a deflected shot after 16 minutes.
Genoa were desperately unfortunate to concede a second when goalkeeper Sebastien Frey saved Mauro Icardi's drive at the near post, only for the ball to ricochet on to team-mate Cesare Bovo and into the net from six metres.
Genoa, who had won five of the last six derbies, pulled one back through Ciro Immobile in the 73rd minute and nearly equalised before teenager Icardi celebrated his Serie A debut by restoring Sampdoria's two-goal lead.
Genoa's sixth defeat in a row left them bottom with nine points while Sampdoria climbed to 14th with 13 points.
Palermo, who have won only twice this season, had goalkeeper Samir Ujkani, midfielder Edgar Barreto and substitute Carlos Labrin dismissed in the second half while Bologna's Saphir Taider was also given his marching orders.
Alberto Gilardino put Bologna ahead with a half-volley and Manolo Gabbiadini and Alessandro Diamanti converted penalties either side of half-time.
Palermo coach Gian Piero Gasperini was told his job was safe despite the well-supported side languishing in 16th place.
"I am absolutely not going to change the coach," Palermo president Maurizio Zamparini, who used three last season and has already fired one this term, told reporters. "Gasperini is not at risk and will stay where he is for a long time."
Promoted Pescara wasted their first penalty of the season when Ante Vukusic's spot-kick was saved by Gianluca Pegolo on the stroke of half-time at Siena.
Already trailing to Francesco Valiani's first-half goal, the visitors lost their heads as Marco Capuano and Damiano Zanon were sent off in the final minutes.
At San Siro, Rodrigo Palacio headed Inter ahead after 10 minutes but Cagliari hit back with two goals from Marco Sau, the first from Andrea Cossu's cross and the second from a rebound after Mauricio Pinilla's overhead-kick hit the post.
Diego Milito had missed an open goal in between for Inter, who snatched a point when the hapless Astori turned Ricardo Alvarez's cross into his own net.