Daniel Berger hit a fine opening round of nine under to take a three-shot lead in the Arnold Palmer Invitational at Bay Hill.
Florida native Berger has been through a run of injury problems - including a back issue which sidelined him for 18 months and then fracturing his right ring finger at the BMW Championship in August last year.
The 32-year-old, though, put those issues to one side as he made six birdies on the back nine to sign for a blemish-free 63, which is one off the course record.
"I think the biggest thing for me is just getting in a bit of a rhythm," Berger said. "When you come back (from injury), you are just kind of getting back into the flow of things and getting into your routine.
"I have really played not that poorly, I just haven't had the results. You just kind of keep doing the same things and good things will come, so that's kind of where I feel like I am at."
Rory McIlroy had to settle for a level-par opening round, with a double bogey proving costly.
After turning well set in 34, McIlroy found the water at the 13th for six and then dropped another shot at the next before making one shot back at the 16th.
The Masters champion, though, hit his second shot on the 18th into the back bunker to finish with another bogey.
World number one Scottie Scheffler finally got another sub-par opening round with a two-under 70, which was a first since he won The American Express in January.
"I did some really good things and I felt like I made a couple mistakes that I shouldn't have," said Scheffler, who finished joint-12th in his last event at the Genesis Invitational.
"But overall I did some really good stuff out there. Anything under par on this golf course is a decent score."
Justin Rose also sits in a group alongside Scheffler at two under.
Sweden's Ludvig Aberg produced a strong finish to sit at six under, having sunk a long eagle putt on 12 following successive bogeys and then finished with another birdie.
Former Open champion Collin Morikawa is also three shots off the lead following an eagle on the 16th and then successive birdies.
Jhonattan Vegas and Cameron Young are tied third at five under, both players having made a bogey five on the 18th.
Shane Lowry, though, had to settle for a disappointing two-over-par 74 after five bogeys, including one at the 18th.
Tommy Fleetwood also found the going tough, as he finished at four over. The Englishman made a double bogey at the ninth when teeing off to the left, taking a drop in the cart path and then finding the bunker - with three more dropped shots following after the turn.
Coverage from the Arnold Palmer Invitational continues on Friday March 6 from 3.30pm on Your Site Main Event and Your Site Golf. .
