Seamus Power has work to do to make the cut after opening with a one over 73 on his PGA Tour debit in the Safeway Open at Silverado Resort and Spa's North Course in California.

The West Waterford man hit nine fairways and 13 greens but he never hit the ball consistently close to the hole and had 30 putts, ending the day tied for 100th and 11 shots off the lead.

Scott Piercy made 12 birdies and two bogeys in a 62 to lead by two shots from Paul Casey and Patton Kizzire on 10 under par.

Power, who began on the back nine, was one under through seven holes but bogeyed the 17th from the middle of the fairway and after holing a 20 footer for par from the fringe at the 18th, three putted the first and and failed to get up and down from sand at the par-three second.

He got a shot back at the 407-yard fourth, holing an 11 footer. But it was significant that his only other significant successful putt was a 10 footer for par at the ninth, where he was forced to take a penalty drop after driving through the fairway into trouble and had to get up and down from 116 yards for his par five.

Phil Mickelson is tied 21st after a three under 69.