Los Angeles - Bill Haas defied difficult weather conditions to thrust himself into contention on Friday at the PGA Tour's Safeway Open, where Scott Piercy remained atop the leaderboard when darkness halted the rain-delayed second round.
Haas, playing in the marquee group on Thursday and Friday with Phil Mickelson and defending champion Emiliano Grillo, teed off early in the worst of the wind and rain in Napa, California, north of San Francisco.
They played just three holes before play was suspended.
"If we had not gotten to stop, it would have been very difficult for us," Haas said. "Those three holes we started with this morning were very difficult. You couldn't really even see your ball, it was raining and windy."
After a delay of more than two hours, Haas returned and completed a two-under par 70 that gave him an eight-under total of 136 and the clubhouse lead.
Piercy, who fired a course-record 62 on Thursday, was four-under through 10 holes when play was halted, and atop the leaderboard on 14-under par.
Piercy's day was highlighted by a hole out for eagle at the par-five ninth hole.
American Johnson Wagner was 12-under through 14 holes and England's Paul Casey was 11-under through 12 when play was halted for the day.
Casey was three-under for the day after five birdies and two bogeys.
World number 12 Casey - who finished the 2015-16 season with back-to-back runner-up finishes and a fourth-place at the US PGA Tour Championship - says he's looking at the first tournament of the US PGA Tour's 2016-17 season not so much as a fresh start, but as a chance to finish out the calendar year on a high note.
He's seeking his first PGA Tour title since 2009.
While Haas climbed up the leaderboard, playing partner Mickelson survived some wayward efforts off the tee to post a second straight 69 for a six-under total that had him tied for 10th at the end of play.
Mickelson hit only six of 14 fairways and pulled his drive out of bounds at the par-four 13th.
"I certainly didn't drive it the way I need to but that's my game - I'm not the most accurate guy, but I get an iron in my hand and I can make a birdie," said Mickelson, who has made 11 birdies in the first two rounds.
"This is some of the best iron play that I've had," Mickelson said. "Given the challenge that we've had judging distance because the ball is going about 10 to 15 yards less than normal distance, then you've got a little bit of wind, a little bit of rain and soft spongy greens, it's been some of my best iron play."
The tournament at the Silverado resort lost some of its luster when 14-time major champion Tiger Woods pulled out on Monday, after targeting the tournament as his return from an injury absence of more than a year.