Napoli's coach Walter Mazzarri (R) smiles at AC Milan's Antonio Cassano after their Italian Serie A soccer match at San Paolo stadium in Naples Sept 18, 2011. [Photo/Agencies]

ROME - AC Milan head coach Massimiliano Allegri lamented his side's lapse following their 3-1 demolition by Napoli on Sunday.

The defending champions went ahead with a wonderful Alberto Aquilani diving header, but Edinson Cavani's hat-trick turned it all around.

"It was a fairly odd game, as we held possession and took the lead, but it was wiped out immediately by a lucky goal," said Allegri.

"We conceded on the counter, which we knew Napoli were going to do. We also wasted a few opportunities to make it 2-2 and with the third goal Cavani did very well to believe in it.

"It was a strange match in which I'm happy with what the lads did overall, though we need more determination in some moments.

"All this is without taking anything away from Napoli, who played their style and took advantage of the chances we allowed them."

Milan have only one point from their opening two games against Lazio and Napoli, while the 2-2 draw at Barcelona midweek also prompted criticism.

"We're not worried. We all have to relax, know we are a big club who can have a couple of setbacks in terms of result, but the performances were decent. The only concern is that we conceded five goals in the first two Serie A rounds," continued the coach.

"The full-backs have to be faster at getting back to help the defence. We certainly made mistakes on the counter-attack.

"Napoli tended to play on the break, which was unusual considering they were the home team. They are very fast and we should've done better in stopping that weapon.

"The team took the right approach and deservedly took the lead. Unfortunately, we allowed Napoli the opportunities that we knew fully well we should not have given them."

Napoli's Edinson Cavani (R) challenges Clarence Seedorf of AC Milan during their Italian serie A soccer match at San Paolo stadium in Naples, Sept 18, 2011. [Photo/Agencies]

Ddinson Cavani scored a hat-trick to help Napoli demolish AC Milan 3-1 on Sunday.

In a possible early Scudetto showdown, Milan took the initiative early on and broke the deadlock at the 12th minute, as Antonio Cassano whipped in a cross from the right for Alberto Aquilani's diving header into the far top corner. It was his first goal for the Rossoneri and a very well taken one at that.

However, barely 60 seconds had passed when Napoli equalized. Christian Maggio knocked down a free kick for Edinson Cavani, whose first-time shot was low through Christian Abbiati's legs at the back post.

Aquilani's inspired pass released Antonio Nocerino, but Morgan De Sanctis smothered at his feet. At the other end Lavezzi's rapid counter was just a little behind Cavani, allowing Abbiati to recover. Clarence Seedorf's free kick was deflected for a corner.

Napoli took the lead for the first time with a classic counter-attack. Walter Gargano started the run from the edge of his own area and surged forward, rolling across to the left for Cavani's powerful strike high at the near post.

It should have been 2-2 moments later when Cassano won back possession and placed a cross-field pass to send Aquilani clear on goal, but his daisy-cutter was parried by De Sanctis at full stretch. Aquilani went close again from distance, drilling just wide of the upright.

Cavani completed his hat-trick after the restart. Marek Hamsik's shot had been beaten away by Abbiati, but as the move continued El Matador pounced on an Alessandro Nesta clearance to volley in from the edge of the box.

Pato was booked for simulation in the penalty area, but moments later Milan should have had a penalty when Paolo Cannavaro punched Nocerino's cross out of the air. The referee and linesman only awarded a corner. Nesta risked a red card for a reaction foul, as he shoved Salvatore Aronica after the Napoli man had trodden on his foot.

Pato nodded Cassano's cross from the by-line over the bar, while Blerim Dzemaili's sudden blockbuster skimmed the upright. Stephan El Shaarawy was given his Milan debut in place of Aquilani.

Cavani fired straight at Abbiati from a Goran Pandev through ball, then moments later acrobatic Juan Zuniga defending stopped Pato in the Napoli box.