Shane Lowry in contention at Sawgrass after brilliant back nine
Ireland's Shane Lowry wrote his name into the record books with a stunning burst of scoring in the Players Championship thanks to an "emergency" call to his coach.
Lowry was level par halfway through his opening round at Sawgrass before storming home in a tournament-record 29 shots to card a seven-under-par 65.
The 29-year-old, who has recorded just one top-10 finish this season, holed from 35 feet for birdie on the 10th and chipped in for an eagle on the par-five 11th before picking up further shots from inside six feet on the 12th and 13th.
Lowry also birdied the par-five 16th and, after missing from 10 feet on the famous par-three 17th, made his final gain of the day from 12 feet on the 18th to finish two shots behind world number one Jason Day, who equalled the course record with a flawless 63.
"Being honest, I was not very confident starting this week," said Lowry, who missed the cut in the Wells Fargo Championship last week.
"I had a bit of an emergency phone call with my coach this morning before I played. I just wanted to get some feelings off my chest. Things have not been going well and I did not feel comfortable on the golf course. I started okay today and then obviously got going on the back nine and it's always nice to shoot 29 at some stage."
Lowry's 65 was matched by former US Open champion Justin Rose, Bill Haas, Cameron Tringale and Brendan Steele, with Italy's Francesco Molinari and Ernie Els among those on six under par.
Starting on the back nine, Day began his round with three straight birdies and also picked up a shot on the 17th before covering the front nine in 31 to match the course record shared by Martin Kaymer, Roberto Castro, Greg Norman and Fred Couples.
Playing partner Jordan Spieth, making his first appearance since squandering a five-shot lead with nine holes to play in the Masters, had to settle for a 72 after taking five to get down from a greenside bunker on the par-five ninth, his final hole.
Day, whose last competitive score at Sawgrass was an 81 in the second round 12 months ago, revealed he was disappointed to miss out on the outright record after narrowly missing from 40 feet on his penultimate hole.
"I just played solid tee to green and when I got to the green I was very confident with my putter," the 28-year-old Australian said on the PGA Tour website. "Unfortunately it didn't go on eight, I really wanted to hole that putt to try and give myself a birdie on nine to beat the record but I'll take a tie.
"To be honest I just felt tired all day. I was just trying to grind it out as much as possible. It's been a long week because it's been hot the whole week. I just felt tired and that kind of distracted me from anything else."
Rose, who finished a shot outside the play-off at Quail Hollow last week, told Sky Sports: "It was great to come out today and get off to another good start. I think I hit 18 greens (in regulation) and gave myself the opportunities to make some putts and I was able to do that.
"I ordered a new putter a couple of weeks ago and it arrived this week, so it's nice to finally get it and it felt good. The pace felt much better today and I'm happy."
On a day of low scoring, former champion Martin Kaymer, Paul Casey and Russell Knox all shot 68, with Ian Poulter and Matt Fitzpatrick finishing three under and Masters champion Danny Willett a shot further back in his first tournament action since Augusta.
"I have not had a load of time to do a great deal of work so the game was not great, but I dig deep and hit some reasonably good shots," Willett told Sky Sports. "I would have definitely taken 70 yesterday afternoon.
"It's been a bit crazy, it's been a whirlwind. It was nice this morning when we were announced as Masters champion but it was nice to get back on the golf course and inside the ropes because all you have to do is concentrate on the golf.
"It's tiring. Every days seems to be 45 minutes to an hour longer signing stuff and doing extra media and all the stuff that comes with winning a major. You take it on the chin and have to do it."
World number three Rory McIlroy was nine shots off the lead after a 72 containing two birdies and two bogeys, the 27-year-old finishing alongside Rickie Fowler after the defending champion carded a double bogey on the 18th.
The 2004 champion Adam Scott fared even worse on the last, finding the water twice to run up a quadruple-bogey eight and finish one over.