David Duval shot an opening five-under-par 66 yesterday at the Riviera Country Club in Los Angeles to share the Nissan Open lead with with Bob Estes.

Going for his third win in five starts this year, Duval did not shoot even a single bogey. The only hole on which he came close to going over par was on the 14th, where he made a seven-foot par putt. Estes, whose only tour win was in the 1994 Texas Open, had seven birdies and two bogeys on the way to his 68.

The co-leaders did not have much margin for error, with a group of players, including Nick Price, just a shot behind, and a host of others, two time champion Fred Couples and Ernie Els among them, two strokes back with 68s.

Tiger Woods, who won last weekend in San Diego, was also in touch after shooting a 69.

Duval, who has recently returned from the ski slopes, believes that getting away from golf keeps him sharp. He has taken up snowboarding and is now an enthusiast. "I'm really glad I like doing that, because when I get back (to golf), it reminds me just how much I love the game," he said.

Asked if he thought he was going to play well every time out, he replied: "That's certainly my intention. And I think feeling that way helps you to play well."