AC Milan maintained their lead at the top of Serie A after defeating Fiorentina 1-0 at the San Siro on Sunday courtesy of a goalkeeping blunder from Pietro Terracciano. Rafael Leao took advantage of a woeful clearance by Terracciano to fire in a low effort that kept Milan in the driving seat for their first league title since 2011 and increased their lead over rivals Inter Milan to five points – for a few hours, anyway. Terracciano then buried his head in his arms as he sat distraught on the San Siro pitch, while the goal whipped the crowd into a frenzy even though Leao kept his celebration to a minimum – just creating the shape of a heart with his fingers. “It’s the greatest moment for a footballer – to score a decisive goal,” Leao said. “But the most important thing was the victory, because we created a lot and perhaps we were a bit anxious in front of the goal. "We're in fantastic shape right now ... we all need to stay united to make sure we achieve our goal." Defending champions Inter Milan cut their advantage back down to two points later on Sunday after a 2-1 win at Udinese, thanks to goals from Ivan Perisic and Lautaro Martinez. But Stefano Pioli's team are further boosted by their superior Milan derby record which would ensure the seven-time European champions stay ahead of Inter should they end up locked on the same points. Until Leao scored it had looked to be a frustrating day for the hosts, Olivier Giroud missing the first of a series of good chances with 15 minutes on the clock when he somehow fluffed his dinked finish wide after being slipped perfectly through by Franck Kessie. Nerves started to get to the home fans after a series of misplaced passes in good positions curtailed promising attacks, and the huge crowd had their heads in their hands two minutes after the break when Leao smashed over from close range after being fed by Giroud. Kessie then had an angled shot well saved before Theo Hernandez, a constant menace on the left, poked over Sandro Tonali's neat through ball. Zlatan Ibrahimovic was introduced in the 65th minute in an attempt to force the winner, but it was Fiorentina who nearly snatched the lead when Arthur Cabral's 76th-minute header was well saved by Mike Maignan. However Leao made it party time when he collected Terracciano's awful kick, charged towards goal and slotted home a finish which could be crucial to an enthralling title race.