New Zealander Danny Lee slipped up in the second round after sharing the 18-hole lead as South Korean Charlie Wi took control of the Pebble Beach National Pro-Am with a three-under 69 in California on Friday (local time).
After firing a flawless nine-under 63 at the Pebble Beach Golf Links on Thursday, which included two eagles, Lee struggled to replicate his heroics at the Spyglass Hill Golf Course on Friday as he carded a one-over 73.
Lee could only manage to birdie the 1st and 15th holes while bogeys at No.9, 16 and 18 pushed him above par for the round and equal third for the tournament on eight-under.
After shooting a blistering 61 on the Monterrey Peninsula Country Club on Thursday, Wi backed up with a 69 at the Pebble Beach Links to open up a three-shot lead over American Dustin Johnson.
The Korean mixed four bogeys with five birdies and an eagle on the par-four 13th, reaching the halfway mark at 12 under par.
Johnson, who shared the overnight lead with Wi and Lee, fired an even-par round of 72 on the Spyglass Hill course, finishing with birdies on 17 and 18 to remain at nine under overall.
Three-time major winner Padraig Harrington mastered the conditions at Pebble Beach to shoot a six-under 66 and move into a tie for third.
He joins American Brian Gay, who shot an impressive five-under 65 at Monterrey, Lee, Brendan Todd and Fijian Vijay Singh at eight under the card.
Scores are still tough to compare though, as players will play each of the three courses - Pebble Beach, Spyglass and Monterrey - before those who make the cut contest the final round at Pebble Beach Links on Sunday.
A group of nine players are tied for eighth at seven under, including four-time Major champion Phil Mickelson, who had a five-under 65 at Monterrey.
Playing his first event on the PGA Tour this year, Tiger Woods shot a second consecutive 68 to stay in touch at six under.
Aaron Baddeley is the best-performed Australian after two rounds at four-under in equal 28th with nine other players.