John Watson drove a McLaren from near the back of the field yesterday to an impressive victory in the Toyota Grand Prix of Long Beach, Calif.

Watson, a 36-year-old veteran from Northern Ireland, gained the fifth victory of his Formula 1 career, beating McLaren teammate Niki Lauda of Austria to the finish line by 27.993 seconds.

"I think Niki had leg cramps towards the end of the race, so there was no point in him challenging me," Watson said.

Lauda, the defending Long Beach champion and a two-time world champion, started right behind Watson in the 24th spot on the 26-car grid. He stayed with Watson as the eventual winner wove through traffic on the tight course through the streets of downtown Long Beach.

A distant third was Rene Arnoux of France in a turbocharged Ferrari. He was followed by Jacques Laffite of France in a Williams, Marc Surer of Switzerland in an Arrows and, in sixth, rookie Johnny Cecotto of Venezuela in a Theodore . . .

In the Atlanta 500, Cale Yarborough took the lead 28 miles from the finish and kept it to win the stock car race by 1 1/2 seconds over Neil Bonnett.

Yarborough, driving a Chevrolet, started 22nd in the rain-delayed race after a poor qualifying performance. He quickly moved up in the field and took the lead for the first time at the 225-mile mark.

Buddy Baker finished third in a Ford, followed by Joe Ruttman in a Chevrolet and Richard Petty in a Pontiac.