Keke Rosberg finally got his title defence underway with victory at the damp Monaco Grand Prix.
The race was in effect decided before the start in the pit lane. Drizzle had left the track wet but out at sea there were clear blue skies. Most drivers opted to start on wet tyres but Rosberg gambled the weather was improving enough to allow a Cosworth-engined car on slicks to match the wet-shod turbo brigade.
Starting fifth on the grid, he stormed past the four turbocharged cars in front of him and by the second lap was never headed. As the track rapidly dried the wet-weather tyres shredded, forcing a series of pit stops which allowed Rosberg to build an insurmountable lead. Within a dozen laps he had been joined by team-mate Jacques Lafitte.
Patrick Tambay caused a blockage back in the field as he was forced to stay out for almost ten laps on worn tyres as Ferrari sorted Rene Arnoux who had shredded his own tyres. Tambay eventually finished fourth.
An unlikely battle for third between Marc Surer's Arrows and the bulky Toleman of Derek Warwick, who had both started on slicks, threatened to provide a real upset but the pair collided on the harbour straight.
Nelson Piquet's Brabham moved into third which became second when Laffite's gearbox failed. Rosberg coped with an engine that kept cutting out and with kick-back from the steering which blistered his hands but he held on for his second career win. Alain Prost ensured he remained on Piquet's heels in the drivers' championship by finishing third.