Rory McIlroy dropped three shots in his closing eight holes to card a scrappy opening round of 74 at the Valspar Championship in Florida.
The Northern Irishman started with 10 pars but a missed a putt from five feet for double bogey on his 14th hole.
McIlroy carded three over, seven shots behind Canadian leader Corey Conners.
Scotland’s Russell Knox is well placed on two under, while Tiger Woods’ superb tee shot on the par-three 17th gave him birdie as he finished one under par.
Woods struck the flag from 146 yards on his seventh hole but could not convert his birdie putt and eventually made the turn at level par.
An 11ft putt for birdie on the 10th, followed by a smart four on the par-five 11th took him to within two shots of the lead.
But back-to-back bogeys on 12 and 13 hampered the 14-time major winner until a stunning tee shot on the 17th hole left a putt from two feet to haul him within three shots of leader Conners.
“Today was tough,” Woods said. “Trying to pull a club, figure out wind direction, gusts. Into the wind it felt like we were hitting walls. The whole group got fooled a lot today, a tough day all around.
“I’m pleased with every aspect of my game. I drove it well, hit a lot of good iron shots. Overall, I feel I really did well today.”
- Larrazabal’s 38 minutes from bed to tee
Conners, 26, has yet to win on the PGA Tour and leads South Korea’s Kim Meen-whee and Americans Kelly Kraft and Nick Watney by a stroke.
Knox, who last won on the Tour in 2016, is tied fifth, while English trio Paul Casey, Luke Donald and Justin Rose are tied eighth on one under with Spain’s Sergio Garcia and Australia’s Adam Scott.
Birdie from the sand on a frustrating day
McIlroy, 28, arrived at the tournament stating he was “totally ready” for the Masters – the only major he is yet to win – which starts at Augusta National on 5 April.
The world number 12 began his 2018 season promisingly with a tie for third in Abu Dhabi and a runners-up spot in Dubai.
But he has followed those performances by missing the cut at the Pebble Beach Pro-Am, finishing tied for 20th at the Genesis Open and sharing 59th place at the Honda Classic.
In this latest outing at Innisbrook Resort and Golf Club, he drove the ball an average 308 yards – 32 yards more than Woods – but found the fairway just 46% of the time and hit greens in regulation with less than 40% of his approaches.
He responded from double-bogey after a loose putt on his 14th hole by chipping in from a bunker two holes later to deliver birdie, only to give the shot back on his final hole to wrap up a frustrating day.