FedEx St. Jude Classic 2015: Leaderboard Scores and Highlights from Thursday

No Tiger Woods, no Rory McIlroy, no Jordan Spieth mean less national attention for the 2015 FedEx St. Jude Classic. For the likes of Brooks Koepka, Greg Owen and Ryan Palmer, however, it could mean the opportunity of a lifetime.

The trio played Memphis' TPC Southwind six under, shooting matching 64s to hold a one-shot lead over the field following Thursday's first round. Koepka, Owen and Palmer have a combined four PGA Tour wins between them, only one of which has come in the last five years.

Koepka carded eight birdies against two bogeys, most of which came in an eventful front nine. The defending Phoenix Open champion had only one par on the front, going under par on six holes and over on two. Long off the tee throughout the day, Koepka was able to overcome shaky drive accuracy to hit more than three-fourths of his greens.

Shane Bacon jokingly chided Koepka for his solid round:

Koepka's back nine, which was actually his front, was a much more standard affair. He hit a solid approach within 20 feet of the hold on the par-three 11th and took advantage of one of the course's two par-fives with another birdie on No. 16. 

Owen, a 43-year-old who has never won on the PGA Tour, played an almost-flawless round of golf overall. He did not card a bogey and had six birdies, hitting a series of excellent tee shots and approaches. Owen hit fairways at a clip more than three-quarters and had a greens-in-regulation percentage of 88.89.

Palmer went through a similarly solid round, playing the back nine (his front) four under before going out with two more birdies to get his 64. Palmer's true skills lied on the green, where he hit clutch putt after clutch putt to ensure a low score. The Texas native has not won on tour since taking the Sony Open in 2010.

Together, the leaders are one stroke ahead of Scott Brown, Steven Alker, Brian Davis and Richard Sterne.

Brown went bogey free and had five birdies, atoning for a poor driving day with solid work on the green. Alker was all over the place, carding eight birds and three bogeys. Like Koepka, he had a nine-hole stretch where he posted only one par. Davis and Sterne combined for one bogey between themselves to stick close to the leaderboard. 

Among the few notables taking part in the final pre-U.S. Open tournament is Phil Mickelson, who is four strokes behind at two under. Mickelson started out red hot, birdieing four of his first seven holes to make the turn at 31.

But like nearly every tournament this year, every two steps forward came with another couple back. Mickelson bogeyed both par threes on the front nine (his back) and finished the day hitting an abysmal 35.71 percent of his fairways.

"I had a good couple of days trying to work on my game and I'm curious to see how that pays off because I really like the golf course here," Mickelson told reporters. "But you never know until you get in competition and have to put forth your best effort."

Mickelson is coming off a 65th-place finish at the Memorial Tournament and has only two tournaments all season where he's been inside the top 10. Luckily, one of those was the year's first major. But Mickelson looks like a real long shot to capture his first U.S. Open and complete the career Grand Slam next week.

As for St. Jude, Mickelson is the highest-ranked player remaining in the field. Dustin Johnson played nine holes Thursday before withdrawing because of an undisclosed illness. Johnson bogeyed his first three holes before parring his next six.

“Something was wrong, you know, starting the fourth hole. I saw him talking to the official,” playing partner Ben Crane said, per PGATour.com. “Clearly, he wasn’t feeling good. He was very cordial and come over on nine, ‘Hey, man, I’m not going to make it the rest of the week. Good luck, keep playing well.’”   

Other notables in the field include Billy Horschel (plus-one), Webb Simpson (minus-one) and Harris English (minus-one). Mickelson is the only top-20 player, and there are no top-10 players remaining after Johnson's withdrawal. Luckily, Koepka and Co. appear willing to take advantage of the opportunity.