Hideki Matsuyama put together a 69 to keep seventh place but dropped six shots off the pace after the third round of the Frys.com Open on Saturday.
Matsuyama had six birdies and three bogeys at the par-72 Silverado Country Club North and was at 10-under 206 for the tournament, six strokes adrift of South Korea's Bae Sang-moon.
"My tee shots were no good at all and I flapped around a bit," said Matsuyama. "A bit of a gap has opened up with the leader but if I can play like I did in the first and second rounds I'll have a chance (of winning the title)."
Bae, who started the day tied for second with American Zachary Blair, shot a 65 to take the lead at 16 under while Blair was second, four shots back.
Ryo Ishikawa had an eagle, four birdies and one bogey in a 67 and moved from 47th up to 17th place.