Promoted Sicilian side Messina upset Italian champions AC Milan with a 2-1 victory at the San Siro in Serie A action on Wednesday.
Riccardo Zampagna gave Messina -- back in the top flight after 39 years -- another shock win following Sunday's 4-3 victory over AS Roma.
Early leaders Juventus kept up their 100 percent record with a 3-0 win at Sampdoria but Roma's troubles continued as they were held to a 2-2 draw at home to Lecce.
Inter Milan got their first victory of the season in dramatic fashion, a superb 87th minute solo strike from Brazilian forward Adriano giving them a 3-2 win at Atalanta.
Milan had not lost at home in the league since a defeat to Udinese more than eight months ago and must have thought they were heading for another positive result after Giuseppe Pancaro headed them in front after 54 minutes.
But within a minute Messina had pulled level through Domenico Giampa who burst through the middle of the Milan defence before firing past Dida.
Just four minutes later the Sicilians, who had not won on their previous two visits to Milan, went ahead when Zampagna headed Alessandro Parisi's cross home.
He also scored the winner against Roma on Sunday and along with Lecce's 18-year-old Bulgarian Valeri Bojinov has become one of the surprise packages of an unpredictable season so far.
Bojinov was on target again for Lecce as they produced an excellent display to maintain their unbeaten start to the campaign.
Roma wasted a chance to pull level on the stroke of halftime when Francesco Totti's attempt at a chip from a penalty backfired embarrassingly as his gentle shot fell into the arms of Lecce keeper Vincenzo Sicignano.
Antonio Cassano brought Roma level, though, in the 54th minute only for Bojinov to restore Lecce's lead with a brilliant lob five minutes later.
Brazilian Mancini earned Roma a point in the 72nd minute, slotting home after great work from Egyptian Mido.
Alessandro Del Piero put Juve on the way to their third straight win of the season with a 19th minute penalty at Sampdoria.
Swedish international Zlatan Ibrahimovic added the second in the 69th minute before Frenchman David Trezeguet completed the win with a goal three minutes from the end.
Inter struggled in Bergamo against Atalanta, going behind to a 25th minute Igor Budan goal after a dreadful back-pass from Inter's debutant defender Nicolas Burdisso.
Dejan Stankovic brought Inter level with a fine header nine minutes after the break before substitute Alvaro Recoba put Roberto Mancini's side ahead in the 79th minute with a smart turn and shot from the edge of the area.
Inter's hopes of a win looked to have been dashed by an 85th minute goal from Atalanta's Giampaolo Pazzini but then Adriano struck to maintain his record of scoring in all six games in Europe and Serie A this season.
The powerful Brazilian picked up the ball wide on the halfway line and after beating defender Cesare Natali, with what Atalanta claimed was a foul, he cut inside and fired a low shot under the body of goalkeeper Massimo Taibi.
Lazio won 2-0 at Brescia thanks to first half goals from Tommaso Rocchi and Fernando Couto but were forced to play the second half with 10 men after Rocchi was sent.