A three under round of 69 at Spyglass Hill took Wi to 15 under, three shots ahead of Ken Duke and four ahead of Woods, who were both five under for the day at Monterey Point and Pebble Beach.

Without a victory in his 18 years on the PGA Tour, 40-year-old Wi has only ever led twice at this stage before, not that he is worried.

"It's a lot more fun than trying to come from behind," said the Korean-born Californian. "That's what we play for and I'm really excited."

In recent weeks, leading after three rounds and chasing a maiden title has not been a good mix – Kyle Stanley and Spencer Levin both threw away commanding leads – and Woods will be hoping for a repeat.

Tiger's round was made by five birdies on his outward nine, but he is not the only big name in the hunt.

Phil Mickelson, Hunter Mahan and Dustin Johnson are tied for fourth on nine under, two shots back of Woods.

A shot further back, in a tie for ninth, sits Padraig Harrington, who was 12 under after 13 at Spyglass Hill but dropped four shots in his final four holes, including a double bogey on the second to last.