Red Bull's Sebastian Vettel completed a hat-trick of Korean Grand Prix victories to put himself only one week away from potentially clinching his fourth successive Formula One title.
The 26-year-old's third successive Korean win, and eighth triumph in 14 races, left him 77 points clear of Ferrari's Fernando Alonso with five races - and a maximum 125 points -remaining.
If the German wins in Japan next weekend - as he did last year - and Alonso fails to finish in the top eight - as also happened last year - the championship will be over.
Alonso could manage only sixth place in Korea.
Finland's Kimi Raikkonen finished second ahead of Lotus team mate Romain Grosjean.
