In the mix with a half-dozen other players trying to keep in range of Pat Perez, Byrd ran off five birdies in six holes to start the back nine and finished with a 5-under-par 67 to take a one-shot lead into the final round.

The one hole he didn’t birdie might have been his best putt — a 7-footer with a sharp break to the right into the grain.

“You won’t believe how much this putt breaks,’’ Phil Mickelson said, standing to the back of the green after his own remarkable par. Byrd poured it into the heart, birdied the next two holes and was on his way.

He was at 15-under 201 and will try to win for the third time in the last seven months on the PGA Tour.

Perez had a hard-fought 70, missing fairways early in the round and rarely converting birdie chances throughout the back nine until a slight mistake turned into his best-looking shot. Taking a little off a 7-iron, he pulled it slightly on the 17th and saw it sail right at the flag and stop some 5 feet behind the pin for a birdie.

Former US Open champion Lucas Glover (69) and former British Open champion Stewart Cink (68), who have not won since capturing their majors in the summer of 2009, were three shots back.

The top eight players were separated by five shots, which isn’t much on a Quail Hollow course where last year Rory McIlroy closed with a 62 for his only PGA Tour victory.

Missing from the mix is Mickelson.

The three-time Masters champion was in range and was poised to make a move with a brilliant par save on the 12th, a mini-flop from a downhill lie to a green that ran away and broke sharply to the left. It stopped inches away.

But he flubbed a bunker shot on the 14th to lose an easy chance at birdie, then hit tee shots into the water on the par-5 15th (bogey) and the par-3 17th (double bogey) on his way to a 74. Mickelson has hit five balls in the water this week.

J.B. Holmes had an amazing stretch on the back nine — five shots to play two holes when he holed a 5-iron on the 15th for an albatross, the rarest score in golf, and followed that with a birdie on the 16th.

That led to a 65, although he was six shots behind, along with Ryder Cup captain Davis Love III, who had a 68.

Champions — Mark Calcavecchia gave away nearly all of his big lead in the Regions Tradition, setting up a tight final round at Shoal Creek in Birmingham, Ala.

Calcavecchia shot a 1-under 71 after a sparkling start yesterday 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 a 68.

European Tour — Thomas Aiken (72—208) maintained his lead after a somber third day of the Spanish Open at Terrassa, which was overshadowed by the death of Seve Ballesteros.