Luke Donald fired a seven-under-par 65 to lead the Pebble Beach National Pro-Am by one shot after the second round in California.
The Briton was one of the top college players in the United States but has not won a tournament since joining the USPGA Tour.
"Coming out of college I was one of the best players for four years," said the 26-year old from Hemel Hempstead, UK. "And coming out on Tour and getting beaten every week by a lot of good players can destroy your self-confidence."
Donald has worked in the last off-season on his attitude and self-belief.
"I didn't do anything too different this off-season," he said. "I worked on my self-belief a little bit with Jim Fannin, a sports performance guy who's made me believe in myself a little bit."
Donald's round at Pebble Beach put him on 10 under par at 134.
Tom Pernice, playing at Spyglass Hill, carded a four-under 68 for a nine-under total of 135, tied with JJ Henry (70), Ken Duke (68) and Vijay Singh (68).
Phil Mickelson, the only 2004 winner entered, fired a 68 and is level with Arron Oberholser (67) and Robert Gamez (69) at eight under.
Donald carded eight birdies but bogeyed the final hole, the scenic 18th at Pebble Beach.
"I got a little bit ahead of myself," he admitted. "A 63 at Pebble sounded so inviting I got a little too aggressive on that one."
Donald is coming off a year in which he made 17 of 27 cuts to earn over £500,000 (€720,000) and finish 90th on the money list.
"I wasn't very pleased with my year last year," he added. "I finished 90th on the money list. It was a drop-back for me from 2002.
"I obviously set high goals for myself this year. I would love to finish in the top 30 on the money list to qualify for the Tour Championship."