South Africa's Retief Goosen overcame the pain of a long-term back injury to claim a share of the lead after the third round of the Transitions Championship in Florida.
Goosen, twice a winner of the event, carded a six under par 65 at Innisbrook Resort to join Jim Furyk (66) at the top of the leaderboard on 11 under par.
Halfway leader Jason Dufner is a shot behind on ten under alongside Korea's Sang-Moon Bae, with Ernie Els and Luke Donald three off the lead on eight under.
Goosen needed just 25 putts to card seven birdies and one bogey as he looks to climb from 52nd in the Official World Golf Ranking to inside the top 50 to qualify for next month's Masters Tournament.
But the former US Open Champion revealed he is not a certainty to play at Augusta anyway after scheduling treatment for his back problem next week.
"It's been a struggle for the last year with my back and I'm going to get some injections done on Wednesday like Vijay (Singh) did and see if that helps," Goosen said.
"I'm struggling around the course. Every shot is a pain in the back but I'm keeping it together."
Goosen added: "It's nice to be back here, it's always great coming back to a course you've done well on before and today was a great round for me. My putter was hot and that's what counts.
"This golf course is one of the best we play on tour and you have to hit the shots, if you don't you're going to struggle, you're not going to get away with hitting it wild. The greens are tricky too."
Goosen and Els (68) were paired together and the former added: "Ernie got off to a great start, I just managed to make a couple more birdies than him coming in.
"It was nice out there talking a little Afrikaans again."
Donald needs to win to reclaim the World Number One spot from Ryder Cup team-mate Rory McIlroy and made the ideal start when he holed out from a greenside bunker for an eagle on the par five opening hole.
However, that was followed by four bogeys and three birdies in an erratic round of 70 to leave the Englishman on eight under overall.
Asked about regaining his status as World Number One, Donald said: "I'm not really focused on it, the aim is to win the tournament and everything else takes care of itself.
"I didn't have it today, but I'm still only three back."
Ireland's Padraig Harrington, who led by three shots after a superb opening 61 - the lowest round of his career - added a 72 to his second-round 73 to lie seven under, four off the lead.
