Golf:Padraig Harrington trails South Korea's Charlie Wi by four shots at the halfway stage of the Pebble Beach National Pro-Am after carding a round of 66 last night. Wi leas on 12 under after a second day which saw Tiger Woods fail to make the most of his chance.

With the weather changing from sunny to drizzle through the day Woods shot a two-under 68 on the easiest of the three courses, the Monterey Peninsula Country Club, to lie at six under at halfway.

Wi took 29 putts but his up and down round included five birdies, an eagle and four bogeys. Dustin Johnson, a winner of the tournament in 2009 and 2010, shot an even-par 72 on Spyglass Hill to sit three shots behind Wi.

Woods was betrayed by his approach play and his putting as he carded a second successive 68. Contesting his first event on the 2012 PGA Tour, the former world number one mixed four birdies with two bogeys on the par-70 Monterey Peninsula Shore Course. Woods found 16 of 18 greens in regulation as early morning sunshine gave way to a mixture of mist and rain but he totalled 33 putts before ending the day at six under.

"The wind was pretty constant all day which was nice," Woods said afterwards. "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 got sliders or downhill putts and the greens started to get a little bit bumpy because of the softer conditions.

"The downhill putts just aren't going to go in, so I had to leave myself in better spots than I did."