Bob Tway knew he had his work cut out for him.

"I felt like I had to shoot a decent score or I'd get lapped," he said.So Tway birdied half the holes he played, shot a 31 on the back nine, finished with a 7-under-par 65 and took the 72-hole lead Saturday in the 90-hole, $1.3 million Las Vegas Invitational.

It was a career-first situation for Tway, who won four tournaments in 1986 but only one more since then.

"It's the first time I've ever been in the lead going into the last round," said Tway, now in his sixth season on the PGA Tour. "I kind of like it."

With a 24-under-par total of 264, he holds a 3-shot lead.

But he knows he can't relax in the exceptionally low-scoring event that has been blessed with what he called "perfect weather and a golf course in ideal condition.

"The guys are just shooting low," he said.

That's an understatement.

Steve Elkington tied the Las Vegas Country Club course and tournament record with a 10-under-par 62. Gene Sauers and Mike Holland shot 63s. Scores in the mid-60's were common and the 85-man field that survived the cut played to an average of 68.04, almost four strokes below par-72.

"With the scores everybody is shooting, 70 won't do it," Tway said in a look-ahead to Sunday's final round of the chance for a $234,000 first prize.

"I've got to shoot a very good round tomorrow or somebody is going to pass me - or a bunch of guys," he said.

Mark O'Meara, a winner last week and the leader through the second and third rounds, shot a 69 and dropped back into a tie for second with John Cook at 267.

"I've never been 21 under par before," Cook said. "If someone had given me that score starting the week, I'd have figured I'd be leading by six or seven shots."

Cook, however, had to shoot a 67 just to stay close.