Formula One world championship leader Lewis Hamilton retired just after halfway through a wet Chinese Grand Prix in Shanghai on Sunday.
The 22-year-old McLaren driver, who needed to finish ahead of defending champion and team mate Fernando Alonso and Ferrari's Kimi Raikkonen to clinch the title, slipped into the gravel as he entered the pit lane.
Marshals tried in vain to shift the bogged down car, with Hamilton keeping the engine running in a futile attempt to escape as the wheels spun.
Raikkonen turned the Formula One title battle into a three-way fight down to the wire with victory in China. Hamilton's double world champion team mate and closest title rival Fernando Alonso finished second with Ferrari's Brazilian Felipe Massa third.
On an afternoon of delight for Ferrari and heartbreak for Hamilton, who had hoped to become Formula One's first rookie champion with one race to spare, the Briton's overall lead was trimmed to four points.
Hamilton has 107 points, Spaniard Alonso 103 and Finland's Raikkonen 100 after taking the 200th win of Ferrari's Grand Prix history.
