Rossi delighted the home fans

It was the Italian's third straight Mugello triumph and helped him close the gap on the second-placed Spaniard.

Yamaha's Rossi came from third on the grid to lead into the first corner before duelling with Honda's Gibernau.

With six of 23 laps remaining, rain forced the race to be restarted and Rossi briefly dropped back to fifth, but cut through the field to triumph.

Italy's Max Biaggi, riding a Honda, was third.

Watch race highlights

The result gave Gibernau 86 points, 10 ahead of Rossi who has moved above Biaggi (72) in the title race.

Both Rossi and Gibernau have now won two races this season.

Englishman Shane Byrne took 10th place, with Jeremy McWilliams of Northern Ireland in 16th position.

Standings
1. Gibernau 86 pts
2. Valentino Rossi 76
3. Biaggi 72
4. Barros 48
5. Carlos Checa 36

250cc race results
1 Sebastian Porto (Arg) Aprilia 40min 32.672secs
2 Daniel Pedrosa (Spa) Honda at 6.147
3 Manuel Poggiali (Smr) Aprilia at 8.415
4 Randy de Puniet (Fra) Aprilia at 11.266
5 Fonsi Nieto (Spa) Aprilia at 11.876
6 Toni Elias (Spa) Honda at 11.888
7 Roberto Rolfo (Ita) Honda at 24.398
8 Alex de Angelis (Smr) Aprilia at 27.550
9 Hiroshi Aoyama (Jap) Honda at 28.126, 10
10 Anthony West (Aus) Aprilia at 38.025

125cc race results
1 Roberto Locatelli (Ita) Aprilia 40mins 13.158secs
2 Casey Stoner (Aus) KTM 0.152secs
3 Hector Barbera (Spa) Aprilia at 0.197
4 Andrea Dovizioso (Ita) Honda at 0.573
5 Mirko Giansanti (Ita) Aprilia at 0.595
6 Pablo Nieto (Spa) Aprilia at 0.879
7 Steve Jenkner (Ger) Aprilia at 5.980
8 Mattia Pasini (Ita) Aprilia at 19.206
9 Gino Borsoi (Ita) Aprilia at 28.656
10 Jorge Lorenzo (Spa) Derbi at 28.671