Byrd, who is at 15-under 201, will be going after his third win in the past seven months.
Pat Perez held onto his two-shot lead until the 13th hole. At least he stayed close with a bold tee shot to a back pin on the par-3 17th for a birdie, and he wound up with 70 to get into the final group.
Stewart Cink (68) and Lucas Glover (69), winless since winning major championships two years ago, are three shots off the lead.
CHAMPIONS TOUR: in Birmingham, Ala., Mark Calcavecchia gave away nearly all of his big lead in the Regions Tradition, setting up a tight final round at Shoal Creek.
Calcavecchia shot 1-under-par 71 after a sparkling start in the Champions Tour major, faltering with a double bogey and two bogeys on the final eight holes.
He finished at 12-under 204 for a one-stroke lead over Jay Haas, who shot 68.
Tom Pernice Jr. three-putted the final hole for double bogey to drop two shots back, along with Tom Lehman. Pernice and Lehman shot 68s.
NATIONWIDE TOUR: In Athens, Ga., Aiken native Matt Hendrix is one shot out of the lead in the Stadion Classic. Hendrix had 3-under-par 68 and trails Russell Henley (66) and Troy Kelly (66) after 54 holes.
North Augusta's Scott Brown (70) and ex-Augusta State star Major Manning (72) are nine shots off the lead.
EUROPEAN TOUR: In Terrassa, Spain, Thomas Aiken maintained his lead after a somber third day of the Spanish Open that was overshadowed by the death of golf great Seve Ballesteros.
The South African shot even-par 72 for an 8-under 208, for a two-shot lead.
Four players are tied for second place, including former Augusta State player Scott Jamieson, who had 72.
He's joined in second place by Andres Hansen (69), Romain Wattel (72), and Pablo Larrazabal (73).