MEMPHIS (Reuters) - Sweden's Robert Karlsson shot a five-under-par 65 on Friday to open up a handy three-stroke lead at the halfway stage of the St Jude Classic and remain on course to win the title he just missed out on last year.
"I like this golf course and I played quite well over two days," Karlsson told a news conference.
"I hit a lot of good iron shots today, gave myself quite a few easy birdies. Yesterday I played the par-fives a bit better, but it's okay."
Knost, who had missed the cut in his past four events, followed up his opening 66 with a 68 while Bradley, who won his first PGA Tour title at the Byron Nelson two weeks ago, continued his great run with a bogey-free 67.
"I played a great round of golf today. I did hit a few funky shots, but when I did, I got it up and down," Bradley said.
"It was just a good solid round. When I got in trouble, I hit great shots."
John Merrick ended the second day in outright fourth at five-under while Sweden's Fredrik Jacobson and American Harrison Frazar were tied for fifth one further adrift after matching Karlsson's 65 as the best round on another hot and humid day at the TPC Southwind.
David Mathis, who led Karlsson by a shot overnight, slipped back in the field after a 72 while world number two Westwood was eight shots off the pace after a 70.