Toseland extended his championship lead

The 26-year-old Briton could only manage fifth place on his Honda in the opener at the Ricardo Tormo circuit.

But with the track drying out after rain over the weekend, he won race two from Max Biaggi and Nori Haga.

He now has 151 points in the overall standings, with Max Biaggi second on 138 and Haga third with 124.

Former champion Troy Corser lies fourth on 101 but title holder Troy Bayliss is back in fifth on 90 points after a first-race third.

Toseland had switched to his second bike for race two after a tyre problem first time out.

The HANNspree Ten Kate Honda rider said: "The second race was awesome. It was a bit close, and I'm just so happy to finish in first place.

"I had a nightmare here last year and I was determined to win. I'd never won (in Valencia), I'd never been close to winning."

Spaniard Ruben Xaus took race one after he came through from a poor start to take the lead at half distance on the Sterilgarda Ducati.

Corser had led in the early stages for Yamaha Motor Italia but Xaus took his time to work his way to the front before pulling away from both Haga and Bayliss.

Corser took fourth ahead of Toseland but it was not a good race for Biaggi as Lorenzo Lanzi and Michel Fabrizio finished sixth and seventh ahead of the Italian.

Haga led race two from the start and Toseland dealt with the early challenge of Xaus to set up a battle with the Japanese rider.

As Bayliss took a trip through the gravel it was left to Toseland and Haga to dispute the lead.

Biaggi had come through from 12th on the grid to lie third and demoted Xaus to fourth before closing in on the leading duo.

Haga made a mistake on the penultimate lap and let Toseland through but the lead changed hands twice more on the final circuit.

Biaggi took his chance on the final lap to pass Haga for second as Toseland held on to take victory.

Xaus was a distant fourth as Lanzi beat team-mate Bayliss to fifth.

Race one leading final positions:
1 Ruben Xaus (Spa) Ducati 37mins 14.606secs
2 Noriyuki Haga (Jpn) Yamaha 37:16.603
3 Troy Bayliss (Aus) Ducati 37:20.936
4 Troy Corser (Aus) Yamaha 37:23.386
5 James Toseland (GB) Honda 37:31.646
6 Lorenzo Lanzi (Ita) Ducati 37:38.878
7 Michel Fabrizio (Ita) Honda 37:40.428
8 Max Biaggi (Ita) Suzuki 37:40.693
9 Josh Brookes (Aus) Honda 37:43.384
10 Roberto Rolfo (Ita) Honda 37:47.360
Selected Others:
23 Dean Ellison (GB) Ducati at 20 laps

Race two leading final positions:
1 James Toseland (GB) Honda 37mins 02.596secs
2 Max Biaggi (Ita) Suzuki 37:02.883
3 Noriyuki Haga (Jpn) Yamaha 37:02.971
4 Ruben Xaus (Spa) Ducati 37:09.233
5 Lorenzo Lanzi (Ita) Ducati 37:10.587
6 Troy Bayliss (Aus) Ducati 37:12.806
7 Josh Brookes (Aus) Honda 37:13.457
8 Regis Laconi (Fra) Kawasaki 37:16.962
9 Troy Corser (Aus) Yamaha 37:18.107
10 Max Neukirchner (Ger) Suzuki 37:22.312
Selected Others:
21 Dean Ellison (GB) Ducati at 11 Laps

Championship standings:
Riders: 1 James Toseland (GB) Honda 151pts
2 Max Biaggi (Ita) Suzuki 138
3 Noriyuki Haga (Jpn) Yamaha 124
4 Troy Corser (Aus) Yamaha 101
5 Troy Bayliss (Aus) Ducati 90