Stuttering Lazio relaunched their Serie A campaign by dominating Roma 3-2 in a rain-lashed Rome derby, as high-flying Fiorentina piled the pressure on AC Milan and Napoli fought back to beat Genoa 4-2 on Sunday.
Inter Milan have a chance to close the gap on leaders Juventus to just a point when they face Atalanta away in Sunday's late match.
But the battle behind the two favourites for this season's scudetto gathered pace as both Lazio and Napoli made up for recent setbacks.
Roma got the perfect start when midfielder Erik Lamela sneaked in behind Lazio's defence to head a corner past Federico Marchetti at the back post.
Heavy downpours ensued, making play difficult but Lazio weathered the storm to get back on level terms in the 35th minute.
Antonio Candreva stepped up for a freekick and hit a piledriver from 35 yards that rocketed past the defensive wall and beat Mauro Goicoechea in the Roma net.
Germany international Miroslav Klose then made amends for a miss moments earlier when he latched on to a pass-shot from Brazilian Hernanes to beat Goicoechea from close range to level.
Roma were stung minutes into the second half when Daniele De Rossi was given a straight red card for a punch-slap to the face of Stefano Mauri as the pair tussled in the area.
Mauri doubled Roma's agony when he pounced on a defensive mistake to put Lazio 3-1 up.
Roma fought back and reduced arrears in spectacular style when Miralem Pjanic hit a long-range freekick in the 90th minute which beat retreating 'keeper Marchetti - but it proved too little too late.
Napoli, meanwhile, cemented third spot after a valiant fight back from Ciro Immobile's 23rd minute opener for Genoa took them to a 4-2 win.
Former Genoa defender Giandomenico Mesto levelled for the visitors in the 54th minute, but Napoli were stunned when midfielder Andrea Bertolacci restored Genoa's lead a minute later.
Napoli's Edinson Cavani was showing great movement throughout and the Uruguayan striker was rewarded in the 79th minute when he rounded the defence to level.
Slovak midfielder Marek Hamsik virtually secured the points with a goal on the stroke of full-time but striker Lorenzo Insigne added a fourth in injury time to leave Napoli third on 26 points, one shy of Inter and five adrift of Juve.
Fiorentina maintained their purple patch with a deserved 3-1 victory over AC Milan at the San Siro.
Milan's defence was virtually absent when former Liverpool midfielder Alberto Aquilani collected a loose ball on the edge of the box following a throw-in to beat Christian Abbiati at his near post.
On the half hour tempers flared when Pato was bundled down in the box by Argentine Facundo Roncaglia. Milan were awarded a penalty, but Pato sent his effort over the crossbar.
That miss proved costly when Fiorentina doubled their lead in textbook fashion on 38 minutes.
Borja Valero collected the ball from a throw-in on the left flank, outpaced Riccardo Montolivo on his way into the area and dribbled past Philippe Mexes to beat Abbiati at his far post.
Bojan Krkic came on in place of Dutchman Urby Emanuelson at half time but it was another substitute, Giampaolo Pazzini, who grabbed Milan's consolation goal on the hour when he pounced on a rebound off the post to beat Emiliano Viviano.
Fiorentina remain fourth on 24 points while Milan's sixth defeat of the season leaves the Rossoneri languishing in 13th on 14 points.
Torino grabbed a precious 1-0 win at home to struggling Bologna while Parma and Siena shared a scoreless draw.
Udinese's solid start to the campaign continued when they grabbed a precious 2-2 draw away to Chievo thanks to Gabriele Angella's second goal of the match in injury time.