American Jason Dufner leads the way at the Byron Nelson Championship in Irving, Texas.
The 35-year-old carded 69 on his third round to stay one shot ahead of countrymen J.J. Henry and Dicky Pride who were tied with Australian Jason Day.
Dufner shot birdies on the sixth and 14th hole following an early birdie on the third to regain the lead which he had shared in a four-way tie earlier in the day.
A 16th-hole eagle and a 17th-hole birdie rocketed Vijay Singh into contention on six under, with the veteran Fijian going round in a four-under 66 on Saturday.
A final-hole bogey was all that prevented him from being on the leader's shoulder overnight.
Swede Jonas Blixt was also boosted up the rankings thanks to a three-under-par round of 67 to share sixth place with Marc Leishman ahead of an eight-way all-American tie for eighth place.
That group included Matt Kuchar, last week's winner at Sawgrass who is chasing back-to-back titles.
Further down the leaderboard, Ireland's three-time major winner Padraig Harrington is three under after a par 70 on Saturday, with Phil Mickelson a shot further back.
Greg Owen is England's highest-ranked player on two under par after a round of 70 to leave him in equal 21st place.
Collated third round scores & totals in the USPGA Tour HP Byron Nelson Championship, TPC Four Seasons Resort and Club Dallas at Las Colinas, Irving, Texas, United States of America
(USA unless stated, par 70):
202 Jason Dufner 67 66 69
203 J J Henry 68 68 67, Dicky Pride 66 68 69, Jason Day (Aus) 68 68 67
204 Vijay Singh (Fij) 68 70 66
205 Marc Leishman (Aus) 65 69 71, Jonas Blixt (Swe) 68 70 67
206 Pat Perez 67 67 72, Matt Kuchar 66 68 72, Scott Piercy 66 70 70, Keegan Bradley 67 68 71, Bob Estes 73 68 65, Joe Durant 70 71 65, Ryan Palmer 64 70 72, Rich Beem 68 70 68
207 Andres Gonzales 66 72 69, Chad Campbell 68 66 73, Jimmy Walker 70 68 69, Jason Bohn 70 70 67, Padraig Harrington (Irl) 68 69 70
208 Phil Mickelson 70 69 69, Billy Mayfair 69 68 71, Ken Duke 69 67 72, Greg Owen (Eng) 67 71 70, Shane Bertsch 70 70 68, James Driscoll 67 71 70, Graham Delaet (Can) 71 68 69
209 Charley Hoffman 66 69 74, Tim Herron 70 72 67, Robert Garrigus 71 70 68, John Mallinger 70 70 69, Charles Howell III 68 73 68, D.A. Points 68 69 72, John Rollins 71 67 71, Nathan Green (Aus) 68 71 70, Ernie Els (Rsa) 70 69 70, Andres Romero (Arg) 72 67 70, David Mathis 68 71 70, Roberto Castro 74 67 68
210 Danny Lee (Nzl) 71 71 68, John Merrick 71 70 69, Bill Lunde 66 75 69, Boo Weekley 69 68 73, Brandt Jobe 70 69 71, Derek Lamely 69 70 71
211 Brian Davis (Eng) 73 65 73, Duffy Waldorf 72 70 69, Greg Chalmers (Aus) 70 71 70, Hunter Haas 69 73 69, Gavin Coles (Aus) 71 69 71, Todd Hamilton 70 70 71, D.J. Trahan 72 68 71
212 Seung-yul Noh (Kor) 73 69 70, Scott Brown 70 69 73, Erik Compton 70 71 71, Gary Woodland 68 70 74, Nick O'Hern (Aus) 70 71 71, Blake Adams 66 71 75, Ricky Barnes 67 71 74, Kevin Kisner 67 74 71
213 Mathew Goggin (Aus) 69 71 73, Kyle Reifers 70 72 71, Brian Gay 71 71 71, Chris Couch 68 70 75
214 Chris Riley 67 74 73, Arjun Atwal (Ind) 72 69 73, Richard H. Lee 68 72 74, Ryuji Imada (Jpn) 67 68 79, Jhonattan Vegas (Ven) 67 74 73, J.J Killeen 70 72 72, Alex Cejka (Ger) 65 73 76
215 Robert Gamez 74 68 73, Harrison Frazar 68 70 77
216 Alexandre Rocha (Bra) 69 72 75, Bobby Gates 71 70 75
217 Tim Petrovic 67 74 76, Rocco Mediate 70 71 76
218 Jerry Kelly 68 71 79
220 Stephen Gangluff 71 71 78
