Miami - World No 1 Jason Day of Australia completed a 36-hole course record effort on Saturday to seize a four-stroke lead entering the third round of the PGA Tour's Players Championship.
Day, a winner of six of his prior 16 starts, birdied the 15th hole and added three pars to finish a second-round 66, six-under par, to stand on 15-under 129 after 36 holes at the TPC Sawgrass layout.
Another Australian, Greg Norman, had established the 36-hole Players record of 130 in 1994.
"(Got) the 36-hole scoring record, which is nice, but I can't lose focus," Day said. "I've got to knuckle down and keep scoring well."
Day's four-shot halfway lead over Ireland's Shane Lowry was also a new mark for the event, one shot lower than the old record margin set by Norman in 1994 and American Lanny Wadkins five years earlier.
"I'd like to say I'm confident but I'm trying to focus and get the right things done out there," Day said. "I've got a pretty sizeable lead now. I'm going to do my best to try and stretch that lead."
World number two Jordan Spieth, who defends his US Open crown next month at Oakmont, missed the cut for the second year in a row in his first event since a Sunday back-nine fade cost him a second consecutive Masters title last month.
"I don't think there's much of a connection to the Masters. I just didn't putt well," Spieth said. "Augusta seems like a long time ago to me."
The tournament was set to get back on schedule Saturday by playing the third round in threesomes off the front and back nines.
"It's going to get tricky out there," Day said. "We're not going to score as well as we have the first two days."
Day could match Norman and Tiger Woods as the only golfers to win the Players while atop the rankings, but he has only two wins in nine tries with a 36-hole PGA lead - last year's BMW and this year's Arnold Palmer Invitational.
After matching the 18-hole course record with a 63 Thursday, Day went five-under for 14 holes on Friday before a storm delay and darkness left him in the 15th fairway on 14-under overall.
When play resumed Saturday morning, Day dropped his approach 15 feet from the cup and curled in the putt for his third birdie in a row on the round.
"I'm actually glad I stopped halfway down the fairway at 15 before hitting my wedge shot," Day said. "I don't think I would have stopped it where it was."
Day, who won his first major title at last year's PGA Championship, missed a 10-foot birdie putt at the par-5 16th and at 17 two-putted from 53 feet for another par.
Seeking his first career bogey-free 36-hole start, Day found the right rough off the 18th tee, was just short of the green with his approach, then pitched the ball inches from the cup and tapped in for par.
"I'm very happy to go through that stretch of 16, 17 and 18 at par," Day said.
Spieth, 22, was a playing partner of Day, 28, and looked as miserable watching the Aussie sink his birdies the first two rounds as he did handing over the green jacket to England's Danny Willett last month at Augusta National.
"It's tough when you are getting shellacked by 15 shots in the same group," Spieth said. "You see all those birdies going in and you wonder why you aren't making any of them. It's tough seeing every hole being birdied and not being able to do much about it."
"I'm striking the ball great. I just need to grind on my short game. If I putt anywhere near the standard I normally putt I'm at 6- or 7-under just on the greens."
Spieth also said he needs to have more fun during rounds and change his attitude if he hopes to approach the success he enjoyed last season.
"I'm beating myself up a little too much on the course and it's affecting me," Spieth said. "I need to lower my expectations a little bit. It seems I'm a little tense."
Leading scores on Saturday after completion of the second round of the US PGA Players Championship (par 72, USA unless noted):
129 - Jason Day (AUS) 63-66
133 - Shane Lowry (IRL) 65-68
134 - Jonas Blixt (SWE) 67-67, Alex Cejka (GER) 67-67, Cameron Tringale 65-69
- Boo Weekley 66-69, Colt Knost 72-63, Francesco Molinari (ITA) 66-69,
Jerry Kelly 67-68, Gary Woodland 67-68, Russell Knox (SCO) 68-67
136 - Zach Johnson 67-69, Rory McIlroy (NIR) 72-64, Brooks Koepka 66-70, Jason Dufner 70-66
137 - Ryan Palmer 67-70, Sean O'Hair 70-67, William McGirt 72-65, Ian Poulter (ENG) 69-68
- Bryce Molder 70-68, Scott Piercy 70-68, Retief Goosen (RSA) 70-68,
Sergio Garcia (ESP) 72-66, Justin Thomas 70-68, Adam Scott (AUS) 73-65,
Matt Kuchar 71-67, Brendon de Jonge (ZIM) 71-67, Kevin Chappell 71-67,
Bill Haas 65-73, Danny Lee (NZL) 67-71, Daniel Berger 66-72, Billy
Horschel 68-70, Jhonattan Vegas (VEN) 67-71, Bernd Wiesberger (AUT)
71-67, Kim Si-Woo (KOR) 68-70