Napoli allowed the chasing pack to gain ground in the race for a Champions League place when they slumped to a 2-0 defeat at Bologna on Sunday.

Alessandro Diamanti opened the scoring in a first half otherwise dominated by the visitors, and Matteo Rubin made the game safe in the second half.

The match ended with red cards for Bologna's Archimede Morleo and Blerim Dzemaili for fifth-placed Napoli, who are now level three points behind Udinese and also have Inter Milan breathing down their necks.

No such setback appeared likely when Marek Hamsik and Juan Zuniga tested home keeper Federico Agliardi in the opening 10 minutes.

Paolo Cannavaro then fired over from distance before Bologna took an 18th-minute lead against the run of play, Robert Acquafresca teeing up Diamanti to finish left-footed from near the penalty spot.

Edinson Cavani and Zuniga both shot wide before Bologna's Diego Perez drew a good save from Napoli keeper Morgan De Sanctis.

Agliardi and De Sanctis saved from Cavani and Marco Di Vaio respectively before Napoli's Walter Gargano ended the half by shooting wildly over the bar.

Gokhan Inler began the second period in identical fashion and as Napoli's frustration grew, Bologna took control from the hour mark.

Diamanti shot just wide but Di Vaio set up Rubin to hammer home the second from a narrow angle in the 64th minute.

Zuniga failed to threaten Agliardi's goal and Di Vaio could have extended Bologna's advantage, but his right-foot shot came back off the left-hand upright.

The same player shot wide before De Sanctis saved from Rubin in the last bit of goalmouth action.

There was still time for a late flashpoint, however, with Dzemaili and Morleo coming to blows a minute from time to win the race to their respective teams' showers.