Los Angeles - Johnson Wagner chipped in for one of his three birdies to grab a one-shot lead on Saturday at the soggy Safeway Open, where rain brought the third round to an early halt.
Wagner was 15-under through 15 holes when the round was halted with darkness closing in and heavy rain causing puddles on the greens.
Second-round leader Scott Piercy, who had fallen one off the pace, was off the 16th green when he told tournament officials he couldn't play his shot because of the water.
Those who failed to finish were due to return early Sunday to complete the round, with the third round to be played in threesomes off two tees in a bid to beat more expected inclement weather.
When play was halted, Patton Kizzire was also at 14-under through 16 holes.
England's Paul Casey was 13-under through 15 holes and Scotland's Martin Laird 12-under through 16.
Michael Kim was the leader in the clubhouse after a 65 on the Silverado Resort course in Napa, California, for an 11-under total of 265.
Wagner, who collected three top-10 finishes in 26 starts last season, is in search of a fourth career US PGA Tour title and his first since the 2012 Sony Open.
Piercy, who finished tied for second behind Dustin Johnson at the US Open in June, returned to the course early Saturday to complete his second round, playing six holes and stretching his lead to three shots over Wagner and Casey.
He was one-over after two bogeys and a birdie in his first 15 holes of the third round.
The tournament lost some of its luster when 14-time major champion Tiger Woods pulled out Monday, having earlier targeted the tournament as his return from a back injury that has sidelined him for more than a year.