Rome, Jan 18 - A Ronaldinho hat-trick helped AC Milan beat 10-man Siena 4-0 Sunday to draw within six points of Serie A leaders Inter Milan a week before a crucial city derby at the Giuseppe Meazza.

Inter risked defeat Saturday at promoted Bari, but managed to claw back a 2-2 draw for a 46-point tally from 20 games, while Milan lie on 40 with a game in hand.

Fast and unpredictable as in his best years at Barcelona, Ronaldinho tried an unsuccessful scissors-kick early in the game before converting a 14th-minute spot kick that made the game an easy affair for the Devils.

Bottom side Siena last weekend worried Inter despite suffering a 4-3 defeat, but were suicidal this time around when Marco Borriello dispossessed Goncalo Brandao and raced for goal only to be floored by Gianluca Curci in a last-man foul sanctioned with a red card.

Substitute custodian Gianluca Pegolo stood no chance against Ronaldinho's penalty and was beaten again on 28 minutes as Borriello slammed home an amazing volley off a deep Andrea Pirlo feed.

Two more goals from Ronaldinho, a header and a drive he drilled under the bar, delighted the home crowd, who now expect the Devils to avenge a 4-0 drubbing suffered at the hands of Inter in August.

The crisis of injury-ridden Juventus worsened in Verona, where a 1-0 defeat against Chievo was their fourth from five games ahead of a classic home tie with Roma.

The Rome side beat Genoa 3-0 and leapfrogged Juve into third place as striker Luca Toni broke the ice since arriving from Bayern Munich at year's end, scoring a close-range flick and a header after Simone Perrotta's opener.

Napoli are now level with Juve, but could move above Roma if they beat Palermo late Sunday in a southern derby. The Naples side have won their last three game and are unbeaten since the arrival of coach Walter Mazzarri 12 games ago.

Fiorentina stumbled in a 2-1 home defeat to Bologna, newcomers Parma had Daniele Galloppa dismissed in a scoreless draw with Udinese, Sampdoria drew 1-1 with Catania, struggling Atalanta hammered Lazio 3-0 with a brace from Cristiano Doni and Joaquin Larrivey also scored a brace Saturday as Cagliari won 3-0 against Livorno. (dpa)