Smith came home 0.216 seconds in front of Terol, who led a tight battle for the lead until the last eight laps.

BBC: Smith wins to lead championship

The 18-year-old from Oxford started from pole and held off the challenge of Spain's Nicolas Terol, with previous championship leader Julian Simon third.

BBC: Smith wins to lead championship

Basically, the title will be his should he finish ahead of Bradley Smith and 14th or higher if Nico Terol features in the top four.

BBC: Matt Roberts' MotoGP column

Italy's Andrea Iannone won the race in a time of 41 minutes, 10.494 seconds, more than two seconds clear of Nico Terol in second place.

BBC: Simon unseats Smith in standings