Diego Milito reacts afer missing the penalty in a Serie A match between Inter Milan and Atlanta on March 18, 2012.
Inter's hope of gaining a spot for next season's European leagues was dealt a blow as they were held to a scoreless draw at home by Atalanta on Sunday.
Diego Milito missed a penalty in the first half, and Inter never looked settled into the game.
Udinese blew away a two-goal lead and had to settle for a 2-2 draw with Napoli at the Stadio Friuli.
Giampiero Pinzi put the Udinese ahead in the 28th minute with Antonio Di Natale doubling their advantage early in the second half.
Diego Fabbrini was sent off after an hour and Udinese failed to defend their lead with 10 men as two goals from Edinson Cavani, who also missed a penalty, earned Napoli a point.
Udinese coach Francesco Guidolin was also sent off in a tense finale with the draw helping both sides move to just a point behind Lazio in the race for the third place.
A goal 10 minutes from time from Nicola Legrottaglie gave Catania a 1-0 victory over Champions League-chasing Lazio.
Bologna twice came from behind to snatch a 2-2 draw at home to Chievo.
Lecce remain in relegation trouble at the foot of the table after failing to make the most of a flying start against Palermo as the game ended 1-1.
Mauricio Pinilla's hat-trick earned Cagliari all three points and sent Cesena even closer towards Serie B with a 3-0 victory at the Stadio Sant'Elia.
Pinilla opened the scoring in the 14th minute and added two more from the penalty spot as Cesena fell apart, losing both Giuseppe Colucci and Marco Rossi to red cards in the second half.
Two goals inside the final 20 minutes lifted Novara to a crucial 2-0 victory at Siena.
With the win, second-bottom Novara hauled themselves to within eight points of safety with their second win in succession.