Juventus failed to fully capitalise after veteran forward Cristiano Doni produced a masterful display to inspire Atalanta to a stunning 3-1 victory over Jose Mourinho's Inter Milan on Sunday.
Former Arsenal goalkeeper Alex Manninger dropped a clanger as second-placed Juve were held to a 1-1 draw at Lazio in the day's late game to cut Inter's lead at the top to three points.
But it was in Bergamo that the real drama happened as Doni scored a brace and set up the third in a magical first 45 minutes in which Atalanta totally dominated the reigning champions. It was only Inter's second league defeat of the season.
"That was our worst performance of the season, you could compare it with our match in Cyprus in the UEFA Champions League (a 3-3 draw at Anorthosis Famagusta)," said Mourinho. "I can't explain my team's first half hour. When we lose I prefer to speak about how well the other team played but we played so badly in the first half that I prefer to say that we brought this result on ourselves."
The victory, as unexpected as it was one-sided at times, was orchestrated almost entirely by 35-year-old Doni who said: "We played a perfect match, particularly in the first half."
He had the first clear chance of the game, juggling the ball in the box before volleying just wide of the near post. Then on 18 minutes he turned provider, heading the ball back across goal to club top scorer Sergio Floccari who turned Ivan Cordoba and scored with a crisp, low, left-foot finish from inside the area for his 10th Serie A strike of the season. Floccari could have scored a second when he turned Nicolas Burdisso in the box but he could only dig his shot straight into Julio Cesar's arms.
On 28 minutes, Atalanta did double their lead, thanks to a huge slice of fortune, as Doni's free-kick took a wicked deflection off Zlatan Ibrahimovic's arm in the Inter wall to wrong-foot Julio Cesar. Atalanta hit a third five minutes later as Doni rose between Cordoba and Burdisso seven yards out to head home Valdes's cross.
Mourinho threw on forwards Victor Obinna, Adriano and Luis Figo but it had little effect. Although the visitors improved after the break, Atalanta remained the more dangerous team and came within a whisker of a fourth on 55 minutes as Julio Cesar beat out Ferreira Pinto's shot only for Diego De Ascentis to clip the post with the follow up. Adriano did have a couple of efforts but failed to hit the target while Obinna had a great chance late on only to sky his shot before Ibrahimovic finally poked home a consolation from a yard out after a scramble in the box.
In Rome, Juventus keeper Manninger made a hash of a deep Cristian Ledesma free-kick from out wide on the left, coming for it and then watching it sail over his head into the top corner on 24 minutes. Lazio's lead lasted only six minutes as former Aston Villa defender Olof Mellberg headed home from a corner.
Brazilian striker Amauri had several good chances for Juve after the break but Lazio's backline held firm as they edged to within four points of the UEFA Champions League qualification positions. "We want to claw back the points and tonight was a good opportunity but it's not easy to earn points against Lazio. We played well," said Juventus coach Caudio Ranieri.
Genoa moved above Napoli into fourth, and the final UEFA Champions League position, as Bosko Jankovic and Guiseppe Sculli scored in a 2-0 success at lowly Lecce.
Julio Baptista was the hero again as AS Roma inched closer to the top four with a last gasp 1-0 win at Torino. The Brazilian forward scoring a stunning bicycle kick two minutes into injury time that leaves Roma eighth, but just five points behind Genoa.
Napoli lost for the fifth time in a row away from home as two Michele Marcolini penalties earned Chievo a 2-1 victory which took them off the bottom.
Australia midfielder Mark Bresciano scored a brace as Palermo boosted their UEFA Cup qualification hopes with a 2-0 win at Sampdoria.