Tiger Woods carded a two-under-par 70 in his first appearance of the 2019 PGA Tour season at the Farmers Insurance Open, where Jon Rahm set the early pace.
Woods enjoyed a return to form last year, the 14-time major winner ending his five-year wait for a title by claiming the Tour Championship, having impressed at The Open and US PGA Championship.
The 43-year-old made his season bow at Torrey Pines Golf Course – the scene of Woods' record seven Farmers Insurance Open titles though the last came in 2013 – on Thursday.
Woods experienced a mixed opening round in San Diego, with the American star holding five birdies and three bogeys, to be eight strokes adrift of leader Rahm.
In picture-perfect conditions, Woods needed six holes to make his first birdie on Torrey Pines' South Course before collecting another at the ninth, having bogeyed the second.
Woods went par-birdie-bogey-birdie after the turn, and he closed out the day with an 18th-hole birdie.
Rahm starred on the North Course – the Spaniard posting a 10-under-par 62 for a one-stroke lead heading into the second round.
The day belonged to Rahm, who started his round with an eagle before following that up with another eagle and three birdies on the back nine.
Rahm only dropped one shot as he reeled off four successive birdies to stay ahead of world number one Justin Rose.
Also playing the North Course, Rose completed a flawless round, which included seven birdies and an eagle for a 63 alongside Doug Ghim.
Former world number one Jordan Spieth ended the day in outright fifth position, three shots behind Rahm.
Spieth missed the cut at the Sony Open but the three-time major champion fared better on Thursday after recording a seven-under-par 65.
Jason Day opened his title defence with a first-round 67, while Rickie Fowler managed a 73 to be one over.