2012 title leader Jorge Lorenzo celebrated his new Yamaha contract by carving his way through from fifth to first in an entertaining British MotoGP at Silverstone.

The Yamaha star took the lead after racing side-by-side with reigning champion Casey Stoner for five consecutive turns, just after the halfway point of the 20 laps.

Aside from a small scare with five laps to go, Lorenzo safely held his advantage to claim his fourth win in six starts by 2.575sec.

After being passed, Stoner - the only manufacturer rider to choose the softer option (new spec) front - found himself under renewed pressure from Repsol Honda team-mate Dani Pedrosa and Gresini Honda's debut pole sitter Alvaro Bautista.

The pace finally began to tell on Bautista in the closing stages, but Stoner and Pedrosa were locked together to the flag, with Stoner just holding on.

Lorenzo's third win in a row means he is now 25 points (one race win) ahead of Stoner in the standings.

Bautista confirmed a career best fourth place, with early race leader Ben Spies - who led for the opening four laps before running wide and allowing Stoner past - dropping to fifth by the halfway stage, where he remained.

Home hero Cal Crutchlow, who missed qualifying due to a left ankle injury in final practice, began the race from 20th and last on the grid.

The Englishman, who revealed this morning that the ankle is broken and dislocated, steered his Tech 3 Yamaha up to eleventh at the end of lap one and concluded a gutsy ride by passing Ducati's Nicky Hayden for sixth place on the very final lap.

Sunday marked Crutchlow's first home grand race appearance, after being forced out of last year's event due to a broken collarbone in qualifying.

Behind Hayden were Stefan Bradl (LCR Honda), Valentino Rossi (Ducati) and Hector Barbera (Pramac). Rossi was the only manufacturer rider to chose the harder option rear and struggled badly early in the race.

Crutchlow's team-mate Andrea Dovizioso was in the thick of a seven-rider lead group early on, but fell from the podium battle at the halfway mark. The Italian rejoined but finished a lap down, in 19th and last.

Battle of the CRTs was won by Aleix Espargaro after a last-lap showdown with Aspar team-mate Randy de Puniet for eleventh place.

James Ellison, the second of the British riders on the grid, limped away from a highside in morning warm-up and rode his PBM Aprilia to 14th in the race, his second points' score of the year.

Speed Master's Mattia Pasini was the only rider not to finish.

Cardion AB Ducati's Karel Abraham was unfit to ride this weekend due to finger fractures in his left hand sustained in testing at Aragon.

Silverstone was the first event where the new specification Bridgestone slick front tyre became the only construction available.

Round seven of the championship will take place at Assen at the end of the month.

British Grand Prix:

1. Jorge Lorenzo
2. Casey Stoner
3. Dani Pedrosa
4. Alvaro Bautista
5. Ben Spies
6. Cal Crutchlow
7. Nicky Hayden
8. Stefan Bradl
9. Valentino Rossi
10. Hector Barbera
11. Aleix Espargaro
12. Randy De Puniet
13. Michele Pirro
14. James Ellison
15. Yonny Hernandez
16. Colin Edwards
17. Danilo Petrucci
18. Ivan Silva
19. Andrea Dovizioso