Second-round leader Rory McIlroy faltered on day three of the St Jude Classic in Memphis as Nick O'Hern, Davis Love III and John Merrick moved to the head of the leaderboard on six under.
McIlroy was a shot clear of the pack after 36 holes but lost ground after signing for a two-over-par 72.
While the Northern Irishman had a day to forget, Australian O'Hern leapt 11 places to the summit after shooting a second consecutive 67.
He made his move after shooting level-par on the front nine, collecting four birdies and a single bogey after the turn.
Love joined him on six under with his third 68 in as many days - built around four birdies and two bogeys - and Merrick was one under for the day after picking up shots at the 16th and 17th to end his round on a high.
McIlroy, who will defend his US Open title in San Francisco next week, struggled to put a decent sequence together all day.
As if to indicate that inconsistency from the off his first three holes yielded par, bogey and birdie.
He went on to pick up strokes at the fifth, ninth, 10th, 13th and 15th holes but prevented complete meltdown by by birdying on three further occasions - including the final green.
McIlrory is one of six players one shot off the leading trio, joined by Dustin Johnson, Robert Allenby, Kevin Kisner, Chad Campbell and Kevin Stadler.
Johnson and Allenby were the biggest movers in that group, both up 14 places after matching 67s.
JB Holmes, second overnight, is two off the lead after shooting two over par on the day, with nine more players one more back.
Two of those - Sweden's Frederick Jacobsen and American Roberto Castro - shared the best score of the day, 66.
Collated third round scores & totals (USA unless stated, par 70):
204 John Merrick 66 69 69, Davis Love III 68 68 68, Nick O'Hern (Aus) 70 67 67
205 Dustin Johnson 70 68 67, Rory McIlroy (NIrl) 68 65 72, Kevin Stadler 69 65 71, Chad Campbell 68 67 70, Robert Allenby (Aus) 68 70 67, Kevin Kisner 69 66 70
206 J.B. Holmes 70 64 72
207 Luke Guthrie 69 71 67, Jeff Overton 67 72 68, Woody Austin 72 68 67, Dustin Morris 71 69 67, Jeff Maggert 66 68 73, Fredrik Jacobson (Swe) 69 72 66, Ryan Palmer 74 66 67, Roberto Castro 73 68 66, Padraig Harrington (Irl) 68 68 71
208 Seung-yul Noh (Kor) 67 69 72, Daniel Chopra (Swe) 72 65 71, William McGirt 71 69 68, Henrik Stenson (Swe) 72 66 70
209 Bryce Molder 69 71 69, Duffy Waldorf 71 69 69, Shaun Micheel 71 70 68, Ken Duke 68 68 73, Martin Laird (Sco) 72 70 67, Chris Couch 70 70 69, Tim Clark (Rsa) 69 71 69
210 Brendon De Jonge 71 68 71, Bill Lunde 71 68 71, Greg Owen (Eng) 72 67 71, John Peterson 72 65 73, Danny Lee (Nzl) 69 70 71, Sean O'Hair 70 69 71, Cameron Beckman 72 70 68, Boo Weekley 70 67 73
211 Bob Estes 72 68 71, Arjun Atwal (Ind) 67 74 70, Martin Flores 72 70 69, David Hearn (Can) 72 69 70, Billy Horschel 72 69 70, J.J Killeen 68 69 74, Charles Howell III 69 71 71
212 Patrick Sheehan 71 70 71, Paul Stankowski 69 69 74, Robert Garrigus 74 65 73, Bart Bryant 72 70 70, Lee Janzen 68 71 73, Gary Christian (Eng) 70 71 71, Ryo Ishikawa (Jpn) 72 67 73, George McNeill 72 68 72, Craig Barlow 72 68 72, Shane Bertsch 71 68 73, Y.E. Yang (Kor) 68 71 73
213 Kent Jones 72 68 73, Steven Bowditch (Aus) 74 66 73, Gavin Coles (Aus) 70 72 71, John Daly 68 69 76, J J Henry 67 74 72, Troy Kelly 68 71 74, Brett Wetterich 71 71 71, Tommy Gainey 72 70 71, Stuart Appleby (Aus) 72 68 73
214 Mathew Goggin (Aus) 70 71 73, Kyle Stanley 71 70 73, Troy Matteson 70 72 72
215 Robert Gamez 72 69 74, Chris Riley 70 71 74, Omar Uresti 70 72 73
216 Matt Mcquillan (Can) 71 69 76, Neal Lancaster 72 70 74, Will Claxton 72 70 74
217 Zack Miller 70 70 77, Jonathan Fly 78 64 75
