Roma's Serie A title hopes suffered a huge blow as Lazio took the Derby della Capitale honours with an impressive 3-1 victory at the Stadio Olimpico.
Keita Balde Diao scored twice and Dusan Basta claimed his first goal in 75 Lazio appearances as the Biancocelesti claimed their first derby league victory since 2012.
Daniele De Rossi had levelled with a controversial penalty at the end of the first half, when Kevin Strootman blatantly dived while challenging Wallace, but Roma were poor throughout and their misery was completed when Antonio Rudiger was sent off for a high tackle on Filip Djordjevic.
Victory would have seen Roma cut the gap on leaders Juventus to six points after the champions were held to a 2-2 draw by Atalanta on Friday night, but Juve could now retain their title as early as next weekend if they beat city rivals Torino and Roma drop points at AC Milan.
Napoli took advantage of Roma's derby defeat to close to within one point of second place in Serie A with victory over Inter Milan.
Jose Callejon scored the only goal at San Siro just before half-time to give Napoli a 1-0 victory and keep the pressure on at the top while damaging Inter's hopes of European football next season.
Milan's Europa League hopes are under threat after they could only manage a 1-1 draw at lowly Crotone.
The visitors trailed as early as the ninth minute to Marcello Trotta's strike but Gabriel Paletta pulled the Rossoneri level five minutes into the second half.
However, any hopes of snatching a late winner were ended with Juraj Kucka's dismissal.
Crotone remain in the bottom three but are now just four points from safety as Empoli fell to a 3-1 home defeat to Sassuolo.
Federico Peluso fired the visitors ahead after 19 minutes but their lead lasted just five minutes before Manuel Pucciarelli levelled from the spot after Federico Ricci was adjudged to have handled the ball.
However, Alessandro Matri restored Sassuolo's lead after 34 minutes and Alfred Duncan made sure of the points in the second half.
Palermo kept alive their slim hopes of beating the drop with a 2-0 victory over Fiorentina.
Goals from Alessandro Diamanti (32) and Haitam Aleesami (90) secured only a fourth win of the season for Palermo, who sit 10 points from safety with four games remaining.
Bologna produced the performance of the day to see off Udinese 4-0.
Mattia Destro scored twice for the home side, with his goals sandwiching a strike from Saphir Taider on the stroke of half-time. An own goal from Danilo then capped off a miserable afternoon for Udinese.
A Joao Pedro penalty after 23 minutes earned Cagliari a 1-0 win over already relegated Pescara, while Genoa slipped to a 2-1 defeat at home against Chievo.
Giovanni Simeone missed a spot kick for Genoa, but they still went ahead before the interval through Goran Pandev.
However, Chievo turned things around in the second half with goals from Samuel Bastien (60) and Valter Birsa (70), although the result was soured slightly when Fabio Depaoli was sent off in the dying stages for a second bookable offence.