Spain’s Jorge Lorenzo is now well on his way to winning the MotoGP title this year.

He won the weekend’s US Grand Prix at Laguna Seca and ballooned his championship lead out to 72 points over main rival and fellow Spaniard Dani Pedrosa.

After Lorenzo’s Yamaha team-mate Valentino Rossi broke his leg at Mugello, Sunday’s US GP might well have produced the second defining moment in the 2010 MotoGP title chase.

Lorenzo arrived in America with a 47-point lead over Honda’s Pedrosa, who looked in with an excellent chance of claiming his third victory of the season as he led the first 11 laps of the race.

But Lorenzo became ever more threatening and was almost within striking distance of Pedrosa by lap 12 of 32, when the Honda rider suddenly lost the front of his RCV and crashed out of the lead.

It was a pivotal moment, being the first time either rider had crashed out of a race this season.

“It was clever to push Dani to the limit but not easy as well because Jorge is the championship leader and he had the most to lose, he really had to ride at the maximum to do this,” said Fiat Yamaha team manager Wilco Zeelenberg.

Pedrosa’s mistake handed Lorenzo a sixth victory from nine starts and a huge 72 point title lead heading into the mid-season summer break.

“We’re happy Dani isn’t hurt and now we have an amazing 72-point lead as we break for the half-way point of the championship,” Zeelenberg added.

After Pedrosa’s accident, Ducati’s Casey Stoner finished second with Lorenzo’s recovering team-mate, Rossi, in third.

Lorenzo celebrated his latest victory by dressing up in a NASA-type spacesuit and performing a mock moon-walk through the corkscrew gravel, where he planted his Lorenzo Land flag.

“I am so happy to win here at Laguna Seca, it’s something I’ve always dreamed of,” said Lorenzo, who had been injured in his two previous US GP appearances.

“I rode so well today, right on the limit and I had to push very hard to stay in touch with Dani.

“He is always so strong on race day but I knew if I kept the pressure on him then there was a chance he would make a mistake and I would be able to catch him.

“I’m sorry he crashed but from then on it was very easy for me because I had a big gap from Casey.

“I have a big lead in the championship but there is half of the season left and it wouldn’t be the first time a rider has lost the title with such a big lead, so we can’t take anything for granted.

“I am really looking forward to some time to relax now after two very busy months. Thanks to everyone in my team for doing a brilliant job.”

Round 10 of the 2010 championship takes place at Brno on August 15.

US Grand Prix results:

1.  Jorge Lorenzo  ESP Fiat Yamaha Team  43m 54.873s

2. Casey Stoner AUS Ducati Marlboro Team 43m 58.39s

3. Valentino Rossi ITA Fiat Yamaha Team 44m 8.293s

4. Andrea Dovizioso ITA Repsol Honda Team 44m 9.061s

5. Nicky Hayden USA Ducati Marlboro Team 44m 9.474s

6. Ben Spies USA Monster Yamaha Tech 3 44m 13.91s

7. Colin Edwards USA Monster Yamaha Tech 3 44m 35.594s

8. Marco Melandri ITA San Carlo Honda Gresini 44m 42.092s

9. Mika Kallio FIN Pramac Racing 44m 47.686s

10. Loris Capirossi ITA Rizla Suzuki MotoGP 44m 47.687s

11. Roger Lee Hayden USA LCR Honda MotoGP 45m 8.962s

12. Alex de Angelis RSM Interwetten Honda MotoGP 45m 9.539s

DNF:

Aleix Espargaro ESP Pramac Racing

Marco Simoncelli ITA San Carlo Honda Gresini

Dani Pedrosa ESP Repsol Honda Team 998m 0s

Hector Barbera ESP Paginas Amarillas Aspar

Alvaro Bautista ESP Rizla Suzuki MotoGP

STANDINGS after 9 rounds:

1       Jorge Lorenzo      Fiat Yamaha Team 210

2       Dani Pedrosa       Repsol Honda Team 138

3       Andrea Dovizioso Repsol Honda Team 115

4       Casey Stoner      Ducati Marlboro Team 103

5       Valentino Rossi    Fiat Yamaha Team 90

6       Nicky Hayden      Ducati Marlboro Team 89

7       Ben Spies   Monster Yamaha Tech3 77

8       Randy de Puniet  LCR Honda 69

9       Marco Melandri    San Carlo Honda Gresini 53

10     Marco Simoncelli San Carlo Honda Gresini 49

11     Colin Edwards     Monster Yamaha Tech3 48

12     Hector Barbera    Aspar Racing Team 41

13     Loris Capirossi     Rizla Suzuki MotoGP 36

14     Mika Kallio Pramac Racing Team 31

15     Alex Espargaro    Pramac Racing Team 28

16     Alvaro Bautista    Rizla Suzuki MotoGP 25

17     Hiroshi Aoyama   Interwetten Honda MotoGP 18

18     Alex de Angelis    Interwetten Honda 8

19     Roger Lee Hayden        LCR Honda 5

20     Kousuke Akiyoshi Interwetten Honda MotoGP 4

21     Wataru Yoshikawa        Fiat Yamaha Team 1