Palermo's European bid hit by loss to Messina
Rocchi winner for 10-man Lazio
Palermo's drive for a place in the Champions League suffered another setback when they lost 2-0 to Messina yesterday.
Two goals by striker Christian Rigano sunk third-placed Palermo, who have taken only seven points from their last eight games and risk losing one of Italy's four places in Europe's top club competition.
Palermo have 45 points from 27 games, two points more than fourth-placed Lazio, who beat Sampdoria 1-0 and have a game in hand.
Empoli, who have also played a game less than Palermo, continued their bid for a top-four finish by beating Udinese 1-0 to move above Milan into fifth on 41 points.
A derby against their Sicilian rivals was always likely to be a tough test for Palermo, who started well but lost their concentration when referee Nicola Ayroldi turned down a penalty appeal for a foul on David Di Michele in the 42nd minute.
Their players were still protesting three minutes later when Rigano put the home side ahead, turning in an Edgar Alvarez cross at the far post.
Palermo were reduced to 10 men on the hour, Ayroldi showing Andrea Caracciolo a red card for his loud and long protests about a foul.
The striker had come on just two minutes earlier in place of midfielder Mark Bresciano.
Rigano sealed Palermo's miserable afternoon in the 65th minute, Alvarez again providing the cross for the former Fiorentina striker to head past goalkeeper Alberto Fontana.
Lazio showed great character to hang on for their fourth win in a row.
Tommaso Rocchi gave them a first-half lead but the Rome-based club were forced to play with 10 men for the final eight minutes after Brazilian defender Emilson Sanchez Cribari suffered an injury.
Fiorentina also continued their challenge for a place in Europe next season, despite their 15-point penalty for match-fixing, as Luca Toni and Alessandro Gamberini each scored a brace in a 5-1 win over Torino.
The win lifted the twice Italian champions to seventh on 35 points.