Shane Lowry says he is "pretty happy" with an opening round that has propelled him into a tie for third at the Players Championship.

His four-under 68 has the Offaly native three shots off early leader and fellow major winner Sergio Garcia at TPC Sawgrass.

Garcia fired two eagles and four birdies in a seven-under-par 65 to enjoy a two-shot lead over American Brian Harman, with Lowry, Matt Fitzpatrick and Canada's Corey Conners on four under.

Despite closing his round with a bogey, the Open champion expressed delight at his productive first day showing after a difficult start to the PGA Tour season.

"I was happy. I think things have not gone great over the last few weeks, so it's nice to go out there and shoot a decent score," Lowry said.

"I'm pretty happy. I didn't do much different than I have been, holed a few putts that managed to go in. It was quite nice. [It's a] difficult golf course. I watched a bit of the golf this morning and I could see how difficult it was playing but that excites me. That kind of gets me, gets my juices flowing, and I like that type of golf."

Also to his liking was the Sawgrass course, with the 33-year-old impressed by the conditions.

He said: "I love this golf course. This is one of the best we play. And when I arrived here, I missed Bay Hill and arrived here on Sunday, and I came out and did a bit of practice and I couldn't believe the condition it was in. It's one of the best conditioned golf courses I've ever seen. So credit to everyone involved. But, yeah, it's nice to be out there."

Lowry will tee of his second round at 12.51pm Irish time. 

 Sergio Garcia puts his arm around Rory McIlroy on the ninth hole

Rory McIlroy, in contrast, struggled after a 79 that dropped well outside the top 100 on the leaderboard.

The world number eight admitted that it was "very hard" to recover after double-bogeying his opening hole on the 10th, before going on to quadruple-bogey hole 18 at the end of his front nine.

"I mean obviously the big number on 18 didn't help and then doubling the first wasn't helpful either," he said. 

"So yeah, I just think just it's hard to recover when you just haven't played good. I mean regardless if you take that 18th hole out, it still wasn't a very good day."

Graeme McDowell, meanwhile, finished with a one-over 73 and said he was not surprised to see a number of high-profile players struggle around the Sawgrass course.

"They always call this golf course a little bit of superstar killer, right? I feel like this golf course has that reputation," he said.

"I think it's what's great about this golf course because if you play well you can score and if you don't play well it's going to punish you. There is no room to miss out there off the fairway, and we know how much trouble is around these greens that if you're a little bit off you could make a big number, there's a big number waiting for you in a lot of holes out there."

McDowell and McIlroy will get their second rounds underway at 5.27pm and 6pm Irish respectively.

Garcia, who won the Players Championship in 2008 and lost a play-off in 2015, birdied the 15th and eagled the 16th to reach the turn in 33 and finished his round in style with birdies on the seventh and eighth and an eagle on the ninth.

"I've always said it, Valderrama and this course are some of my top favourite ones and for some reason it just kind of fits my eye," Garcia said.

"I see what I want to do pretty much every hole and then it's a matter of doing it, but definitely I feel more comfortable and I’ve done well here. So all those things help."