Robert Karlsson shot a five-under-par 65 on Friday to take a three-stroke lead after the second round of the St Jude Classic.
Karlsson started a stroke behind first-round leader David Mathis and carded six birdies and a bogey to reach nine-under. The Swede, who lost here a year ago in a playoff with Lee Westwood, has played his first six career rounds at TPC Southwind under par with this his lowest score yet.
Colt Knost (68) and Keegan Bradley (67) were tied for second. Bradley, the Byron Nelson Championship winner two weeks ago, is among a few who can earn a spot next week in the US Open at Congressional by winning his second USPGA Tour event since the last Open.
John Merrick (69) was five-under, while Fredrik Jacobson (65) and Harrison Frazar (65) were another stroke back. Brandt Snedeker, the Heritage winner in April, shot a 66 to top the group at 3-under that included Mathis (72).
With 83 making the cut at 2-over, David Toms (5-over) and Sergio Garcia (7-over) were among those who made an early departure for Congressional.
Karlsson came into Memphis ranked 23rd in the world and looking for his first USPGA Tour win in his first full season on tour. He has 11 career European Tour wins, but his best finish this year was a tie for fifth at Colonial.
Starting at four-under and teeing off on the 10th, Karlsson birdied his second hole and finished the back side with birdies on three of the final four holes. He hit an eight-iron to 8 feet on the par-three 11th to set up his first birdie.
He saved par on the 12th, 13th and 14th and then hit a wedge from 106 yards to 7 feet to take advantage of a front pin position on the par-four 15th to start his birdie string.
Karlsson found the rough with his tee shot on the par-five 16th, but he recovered by hitting a wedge from 124 to 5 feet for a second straight birdie. He stuck a seven-iron from 175 yards to 4 feet on the par-four 18th to reach eight-under.
He made the turn and birdied the par-four first after hitting his second shot within 4 feet of the pin despite being 124 yards out in the primary rough. When Karlsson rolled in a 14-footer on the sixth for birdie, he became the first player to reach double digits below par at 10-under.
Karlsson dropped a shot with his lone bogey of the round and just his second this week when he three-putted from 34 feet on the par-three eighth.