KYALAMI, South Africa -- Brazilian Nelson Piquet, dominating the South African Grand Prix with Brabham turbo-charged power and uncharacteristic Latin caution, clinched the Formula One world driver's title Saturday for the second time in three years.
The 31-year-old Brazilian, watching the championship challenge from Frenchmen Alain Prost and Rene Arnoux dashed by the punishing Kyalami circuit, led for nearly 60 laps before turning down the booster and coasting home in third place.
Brabham teammate Riccardo Patrese of Italy took the chequered flag, clocking 1 hour 33 minutes 25.708 seconds for the 77 laps of the 2.56 miles (4.104 km) track at an average sped of 126.8 mph (202-939 kph).
Italy's Andrea de Cesaris, in the points for only the third time this season, was second in the Alfa Romeo, nearly 10 seconds off the pace, with Piquet third ahead of Britain's Derek Warwick in the Toleman, last year's champion Keke Rosberg of Finland in the newly-turbocharged Williams and American Eddie Cheever in the one Renault to finish.
Prost, leading the world title charge going into Saturday's final race, quit after 35 laps with no power in the Renault which had carried him to four wins this year.
Arnoux, the outsider for the crown, pulled into the pits after only nine laps and walked away from the Ferrari as it boiled furiously.
Piquet ended the season with 59 points, followed by Prost (57) and Arnoux (49).
'This championship feels even better than the first' said Piquet, who was champion in 1981.
'I was really happy when Prost quit. As soon as he pulled out I turned down the booster on the turbo charger just to make sure that I finished,' he said.
The Brazilian, who trailed Prost by two points going into the final race, knew after the retirements of the French pretenders he had only to finish fourth or better to be sure of the crown.
'Until the pit stop I was going as fast as I could,' said the quietly-spoken Brazilian who had carved out a lead of more than 20 seconds after only 30 laps.
'Then after that the pits signaled me to take it easy because it was ok and I slowed down. I allowed Nikki Lauda (Austria) and de Cesaris to pass me but if the world championship had not been at stake I know I could have won the race.'
Arnoux, who went into the race with a heavily bruised foot from a pre-race accident, found more bad luck after only two laps when he was forced into the pits with a puncture.
'Then the engine blew,' said Arnoux. 'But that's the race. There is nothing you can do about it.'
French pole sitter Patrick Tambay, driving his last race for Ferrari, pulled off the track at ford corner after 57 laps with a dead engine just as it loked he was certain to be among the points.
Former world champion lauda, in with a chance of adding to his 19 Grand Prix wins after Piquet eased off, was breathing down race leader Patrese's neck in the closing stages before his Mclaren died with only five laps remaining.
Patrese, scoring only the second formula 1 win from 96 outings, said his Brabham ran 'absolutely perfectly, especially over the last 32 laps.
'I hope it might encourage Brabham to keep me on next year,' he said.