Giampaolo Pazzini scored a brace on his debut as Inter fought back from a two-goal half-time deficit to beat Palermo 3-2.
The win kept the scudetto champions in the title race following leaders AC Milan's 2-0 win at Catania yesterday, leaving them nine points behind but with a game in hand.
Fabrizio Miccoli and Antonio Nocerino had given the visitors a 2-0 lead at the break while Javier Pastore hit the post and had a penalty saved for the Sicilians.
But Pazzini's double got Inter back on level terms before Samuel Eto'o smacked home the winner from the spot.
Inter made a blistering start as Maicon's shot with the outside of his right boot flashed just wide on three minutes.
But two minutes later it was Palermo who went in front as Mattia Cassani skipped around Davide Santon and crossed for Miccoli to tap home from close range.
Inter came storming back and Eto'o crossed into the box but Diego Milito arrived a split second too late.
Lucio headed a Miacon corner straight at goalkeeper Salvatore Sirigu while Thiago Motta blazed over.
Palermo went two up on 36 minutes as Inter again failed to deal with a Cassani cross from the right, Nocerino arriving at the back post to turn inside Maicon and beat Julio Cesar at his near post.
Inter immediately put Palermo on the back foot as captain Javier Zanetti and Milito both came close.
But they were vulnerable on the counter attack and Santon blocked a Cassani effort before Cesar got a crucial touch to stop Nocerino rounding him.
Sirigu saved from Motta with Eto'o slotting home the rebound only to be denied by an offside flag.
It should have been three before the break but Pastore's venomous drive crashed back off the upright.
Inter were back on the attack after the break as Sirigu made a brilliant one-handed save to push away Eto'o's 20-yard free-kick.
But then debutant pair Houssine Kharja and Pazzini, both on as second half substitutes, combined to haul Inter back into the game, the Moroccan midfielder chipping into the box and the Italy forward holding off his marker before turning and shooting low past Sirigu.
Cesar kept Inter in the game on 64 minutes as he saved Pastore's penalty after Motta had cynically brought down substitute Pajtim Kasami.
Pazzini grabbed his second 17 minutes from time as he headed home Maicon's free-kick at the near post.
Moments later Ezequiel Munoz was adjudged to have brought down the striker in the box and Eto'o stepped up to sweep home the penalty.
Inter had a miraculous late escape when Federico Balzaretti's fierce goalbound volley clipped Maicon's heel and then Cesar's before flying away to safety.
Napoli remained four points behind table-topping Milan in second as Serie A top scorer Edinson Cavani smashed a hat-trick in their 4-0 thrashing of Sampdoria.
Cavani took a pass from Ezequiel Lavezzi, turned inside his marker and rifled home on 16 minutes before netting a spot-kick just before the break.
Marek Hamsik made the game safe three minutes after the break before Cavani notched his third on 57 minutes.