SPRINGFIELD TOWNSHIP, N.J. -- Jimmy Walker aimed to reclaim some of his 2014 magic entering this weekend's PGA Championship.
After opening with a 5-under-par 65 Thursday, the 37-year-old American is well on his way.
"There were shades of (2014) for sure," said Walker, who sank six birdies opposite a bogey on No. 6 to stake a one-shot lead after the opening round of the 98th PGA Championship on the Lower Course at Baltusrol Golf Club.
The five-time PGA Tour winner collected three of those 'W's' during a milestone 2014 campaign, but the world's No. 48 ranked player hasn't won since claiming last year's Valero Texas Open.
This season, Walker hasn't placed higher than a tie for fourth at January's Farmers Insurance Open. He currently ranks 50th in the 2016 FedExCup standings (752 points) and 57th on the money list ($1,471,771).
"Just a lot of even par to a couple under golf, and it's equated to a bunch of 20th place finishes this year," Walker said.
A win at Baltusrol could check off two goals for Walker: winning his first major championship -- his highest major finish was tied for seventh at the 2014 PGA Championship -- and qualifying for the 41st Ryder Cup in late September.
"I definitely wanted to play Ryder Cup this year," Walker said. "So solid play at the end of the year could get you the nod."
Kaymer's charge was the highlight of the afternoon wave after the former World No. 1 dropped five birdies around a lone setback -- his bogey on No. 2.
"I just didn't miss many fairways and therefore, you can create some birdie chances," Kaymer said.
Open Championship winner Henrik Stenson of Sweden, Harris English, James Hahn and Andy Sullivan of England made up a four-way tie for fifth with 67s.
Top-ranked Jason Day of Australia, the defending PGA champion, equaled last year's opening round score with a 68. Day went on to beat Jordan Spieth by three shots for his first major championship at Whistling Straits in Mose, Wisc.
"I feel pretty good about where my head is at and looking forward to the next three days," Day said.
Day and seventh-ranked Rickie Fowler headlined a large tie for ninth. Fowler's 68 was his second sub-par, first-round score in seven career PGA Championships.
Third-ranked Spieth, meanwhile, posted a 70 with two birdies and a double bogey.
"I struck the ball beautifully today," Spieth said. "One bad tee shot that caused the double bogey, and the rest of it was on the greens."
Willett is in a large tie for 55th, while Johnson is tied for 143rd after his disastrous day.
Johnson also logged a pair of double bogeys during round two of the Open Championship, where he finished tied for ninth.
Fourth-ranked Rory McIlroy of Northern Ireland stumbled to a four-bogey 74 and is tied for 121st. It marked the first time McIlroy went without a birdie since his 77 in round three at the 2016 Masters.
The two-time PGA Championship winner has made the cut in each of his previous seven starts at the event and in 26 of 31 majors overall.
"I have to play a good round to get into the weekend (Friday)," McIlroy said. "I think that's the first objective, and then go from there."
Sixth-ranked Bubba Watson is also tied for 55th after notching a 71, outweighing his three birdies with four bogeys.
Phil Mickelson, who won the PGA Championship at Baltusrol in 2005, also came in at 71 after starting with four bogeys on 11 holes, but recovered with three birdies over his last seven.
The 46-year-old southpaw is two weeks removed from a second-place finish at The Open after his lauded closing round duel with Stenson.
"I've been playing very well at the British and in my preparation," said Mickelson, who is also tied for 55th, "and to come out and hit shots like I hit those first 11 holes was very disappointing."
Round two tees off at 7 a.m. ET Friday, but forecasts predict overnight rainfall and thunderstorms that could cause delays.
"Hopefully we can skirt the weather and be able to get this thing in," Day said.
NOTES: Baltusrol Golf Club is hosting the PGA Championship for the second time in its 121-year history. Phil Mickelson won the 2005 PGA Championship at Baltusrol, claiming a one-shot victory for his second career major win. ... The average age of the 156-player field is 40.25, with Rick Schuller (53) the oldest and Ben Polland (26) the youngest. ... Second-ranked Dustin Johnson could become the world's top-ranked player with a sole second finish or better at Baltusrol if current No. 1 Jason Day of Australia finishes sole 28th or worse. ... Jordan Spieth celebrated his 23rd birthday Wednesday. He was 12 years old when the PGA Championship was last played at Baltusrol. ... South Korea's Byeong Hun An won the 2016 PGA Long Drive Championship Tuesday with 347-yard drive on No. 1, besting Northern Ireland's Rory McIlroy by two yards. It was the furthest roll in the competition since Andy Frank's 346-yard strike in 1982.