Seámus Power has left himself with work to do on his full PGA Tour debut at the Safeway Open in California after shooting an opening round of 73 to sit at one over par.
The Waterford golfer – who earned his full tour playing privileges via the Web.Com Tour – carded two birdies on his front nine but they were nullified by two bogeys.
Consecutive bogeys at the 10th and 11th threatened to derail the 29-year-old’s round but he fought back with a birdie two holes later.
However, that leaves him 11 shots behind early leader Scott Piercy.
Piercy, runner-up at the US Open in June, found his putting touch to reel off 12 birdies for a course record 10-under-par 62 at the Silverado Resort in Napa.
Casey and American Patton Kizzire carded 64.
The event lost its star attraction on Monday when Tiger Woods, who was scheduled to return from a 14-month hiatus, withdrew, saying his game was not sharp enough.
In his absence, most of the gallery followed five-times major champion Phil Mickelson, who missed a two-foot putt at the first hole and also bogeyed the second before steadying the ship for a 69.
But the first day of the 2016-17 PGA Tour season belonged to Piercy, who said he worked diligently on his putting during his short off-season break.
“I think I made more feet of putts than all of last season,” said the 37-year-old from Las Vegas. “Today was a good start to the season, (to) get some confidence with the putter.
“Being 150th on the (putting) stats last season, it gave me a month off, and it was just a matter of figuring out what was going on with the putter, grind away.”
Second-placed Casey continued his sizzling form after finishing second, second and fourth in the final three events of the recently-completed 2015-16 season.
He succumbed to the temptations of the famous wine region pre-tournament, but vowed to remain dry until Sunday night, when he hopes to celebrate what would be his first worldwide victory since 2014.
“I normally have a rule (that) I stop (drinking) on a Monday (but) I extended that through to Wednesday,” said the world number 12.
“I saw an old friend of mine yesterday who’s starting to make wine (and) my caddie, it was his 50th birthday on Tuesday, so we had couple of bottles then.
“It hasn’t hurt yet, but it’s so tough to be here and not sample the fruits. I’m trying to be well behaved.”
American Morgan Hoffman hit the shot of the day, holing out with a long iron from 250 yards for albatross at the par-five 18th, where his ball took a kind bounce into the hole.
