Mike Weir opened up a five-shot lead over Shigeki Maruyama at the end of the third round of the Nissan Open after firing a five-under-par 66 on day three.
The defending champion entered the day in a tie for the lead with his Japanese playing partner before improving to 17 under on 196 at Pacific Palisades in California.
But the Canadian is aware he has not won a tournament in the United States when leading after three rounds.
“I’ve been in the lead going into the final round and I have not done that well,” Weir said. “I’ve got something to prove to myself.”
Weir’s 54-hole total established a new record at Riviera Country Club.
Maruyama was alone in second place at 12 under on 201 after carding a 71 over the 7,260-yard lay-out.
Jeff Maggert was on 202, a stroke clear of Scott McCarron, with John Daly and Briny Baird tied at 204.
Tiger Woods finished the day way back on 210 – 15 strokes off the lead – after matching his opening-round 72.
Last year, Weir came from seven shots back on the final day, to defeat Charles Howell III with a birdie on the second play-off hole.