Defending champion Dustin Johnson made only one mistake during his second round 68, but it cost him the outright lead at the Pebble Beach National Pro-Am Friday. With a clutch of players nipping at his heels, overnight leader Johnson surrendered a one-stroke advantage with a bogey on the 17th to fall back into a tie with five others on 10-under par. Having patiently moved to the head of the pack, the American now jostles for space at the top of the leaderboard with compatriots Bryce Molder, Paul Goydos and J.B. Holmes, along with Germany's Alex Cejka and Australian Matt Jones. David Duval is one stroke behind after shooting a 68 at Pebble Beach Golf Links. Johnson will play his third round at Spyglass Hill, considered the toughest of the three golf courses used in the rotation. Goydos played his second round at Spyglass and had the best round of the day of the leaders, a seven-under 65. It marked the American's first sub-70 round at the course in 14 appearances at the event. Goydos, named an assistant Ryder Cup captain by Corey Pavin, has set a goal to play well enough to get on the team. A strong finish here would get him closer. “Obviously you set goals,” Goydos said. “You should have different levels of goal-setting throughout the year.” Duval was also among the leaders for a brief period, reaching 10-under with a birdie on the sixteenth at Pebble Beach. He fell back to nine-under after a bogey on the par-three 17th. The former world No. 1 has now notched together two sub-par rounds, only the fourth time in the last 24 events. On the three previous occasions, Duval struggled to take the form into the final two rounds, his highest finish a tie for 59th. Stricker top seed In Arizona, embattled world No. 1 Tiger Woods won't play the World Golf Championships Match Play championship next week, and in his absence American Steve Stricker will be the top seed. Woods didn't meet the Friday deadline for confirming his entry in the 64-man tournament, where last year he made his return from knee surgery. World No. 3 Phil Mickelson had already said he wouldn't play the Match Play as he catches up on a family holiday that was postponed because of his wife's breast cancer treatment last year.