Charlie Wi evaded the worst of the weather and birdied three of his last six holes to surge three shots clear in Friday's second round of the Pebble Beach National Pro-Am as Tiger Woods finished six strokes adrift.
South Korean Wi, among three players tied for the lead overnight, fired a three-under-par 69 at Pebble Beach Golf Links, one of three venues being used this week, to post a 12-under total of 130.
American world number 10 Dustin Johnson, tournament champion in 2009 and 2010, was alone in second after carding a 72 on the tricky Spyglass Hill layout.
Fijian Vijay Singh, who returned a 68 at Spyglass, was a further shot back at eight under with New Zealander Danny Lee (73), Irishman Padraig Harrington (66) and Americans Brian Gay (65) and Brendon Todd (69).
In pursuit of his first PGA Tour victory, Wi eagled the par-four 13th, his fourth hole of the day, before ending his round in topsy-turvy fashion - birdie-bogey-birdie-par-birdie-bogey - as mist and then rain swept across the course.
I have some experience playing with the lead, a smiling Wi, who opened with a sizzling nine-under 61 at Monterey Peninsula on Thursday, told reporters.
I took the approach today by telling myself that this is just a new day and whatever happened yesterday that I was going to put it behind me and just start fresh.
The big-hitting Johnson, who has always relished competing on the picturesque Monterey Peninsula, had to negotiate his final holes in the worst weather of the day.
It played really, really hard coming in, he said. It seemed like every hole we played was into the wind, too. It got cold, it was wet and the ball was going nowhere.
But still my score was a lot worse than how I played. I really gave away some shots. I three-putted twice from really close and didn't get up and down a couple of times from right next to the flag.
Woods was also left frustrated after shooting a two-under 68 at Monterey Peninsula, the easiest of the three layouts.
It was decent, the former world number one said after finishing his round in steady drizzle and plunging temperatures. I drove it good again today, unfortunately I just didn't make enough birdies.
The hard part was just getting the ball in there (on the greens) where you could give it a free run. I was hitting the ball in wrong spots.
I am six back so I need to make something happen a little bit over there, Woods added, referring to his third round on Saturday at Pebble Beach Golf Links.
Three-times winner Phil Mickelson carded a 65 at Monterey Peninsula to finish five strokes off the lead, level in a large group with fellow U.S. Ryder Cup player Hunter Mahan (70).
It was an interesting day, said left-hander Mickelson, We had perfect weather and then on the back nine when the (bad) weather came in, I don't know what happened but I started to play a lot better and make some birdies.
In the perfect conditions, I struggled. But to play these golf courses in such great conditions either way has been a lot of fun.