Rossi is closing in on rival Gibernau in the title race

The Yamaha rider, who won his home Grand Prix in Italy last week, snatched the lead from local hero Gibernau with just under two laps to go.

Fellow Italian Marco Melandri, also riding a Yamaha, finished in third.

Gibernau retains the world championship lead on 106 points from five races, but Rossi is just five behind in second.

Rossi, who has had his work cut out since leaving Honda to race for Gauloises, was quickest off the start ahead of pole-position man Gibernau.

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A mistake by Rossi when his rear wheel kicked out going into a corner allowed Gibernau through but the Italian then played a waiting game behind his Spanish rival.

Rossi re-took the lead with nine laps remaining as the leading duo built up a comfortable advantage of over five seconds.

Gibernau then had to take avoiding action as he nearly hit the back of Rossi's machine and then snatched the lead back with four laps remaining.

Gibernau had set a new lap record in Barcelona to claim pole

With two laps to go Rossi was back in front after slipstreaming Gibernau down the finish straight and then held the lead to the finish flag.

Rossi admitted Honda's straight-line power made Gibernau hard to beat, but said he knew he would be faster through the corners.

"We lost on the straights to Honda but it's good for turning," Rossi said of his Yamaha. Second-placed Gibernau defended his tyre choice: "I'd seen in practice the Yamahas were getting better traction.

"I knew if I picked the same tyre as Yamaha I'd not be able to go as fast so I made the right tyre choice for me."

Rossi's team-mate Marco Melandri was relieved after his third-spot finish - his first podium place in MotoGP.

The UK-based rider said: "It's a good day for me. I have been waiting one-and-a-half years for this result."

Britain's reigning World Superbike champion Neil Hodgson was 12th on the d'Antin Ducati, while fellow Englishmen Shane Byrne was 13th for Aprilia and Chris Burns 18th on the WCM.

The 250cc category was won by Frenchman Randy de Puniet on the Safilo Aprilia after a thrilling last-lap battle with Spaniard Daniel Pedrosa on the Telefonica Movistar Honda.

Welsh teenager Chaz Davies finished 13th on the Aprilia Germany machine.

Spain's Hector Barbera won the 125cc race on the Seedorf Aprilia.

Results:

Leading MotoGP positions:

1. Valentino Rossi (Italy) Yamaha 44:03.255
2. Sete Gibernau (Spain) Honda 44:03.414
3. Marco Melandri (Italy) Yamaha 44:17.178
4. Carlos Checa (Spain) Yamaha 44:22.468
5. Colin Edwards (U.S.) Honda 44:24.460
6. Ruben Xaus (Spain) Ducati 44:26.102
7. Shinya Nakano (Japan) Kawasaki 44:27.269
8. Max Biaggi (Italy) Honda 44:27.359
9. Norick Abe (Japan) Yamaha 44:38.931
10. Loris Capirossi (Italy) Ducati 44:44.030

Selected others:

12. Neil Hodgson (Britain) Ducati 44:59.412
13. Shane Byrne (Britain) Aprilia 45:06.934
18. Chris Burns (Britain) Harris WCM 5 laps

Leading 250cc positions:

1. Randy de Puniet (France) Aprilia 41:29.955
2. Daniel Pedrosa (Spain) Honda 41:30.064
3. Toni Elias (Spain) Honda 41:39.476
4. Sebastian Porto (Argentina) Aprilia 41:50.826
5. Fonsi Nieto (Spain) Aprilia 42:04.292
6. Hiroshi Aoyama (Japan) Honda 42:07.524
7. Sylvain Guintoli (France) Aprilia 42:12.042
8. Alex Debon (Spain) Honda 42:15.805
9. Anthony West (Australia) Aprilia 42:15.893
10. Franco Battaini (Italy) Aprilia 42:16.190

Leading 125cc positions