Phil Mickelson missed history-making scores the first two days, but matched the tournament's 54-hole scoring record on Saturday.
Mickelson birdied five of the last six holes in round three for a 7-under 64. His 54-hole total of 24-under-par 189 matched Mark Calcavecchia's record from 2001.
The total of 189 is the second-lowest 54-hole total in PGA Tour history. Mickelson is a two-time winner of this event and owns 40 career PGA Tour victories.
Mickelson had a chance to shoot 60 on Thursday, but his birdie putt on the last hole horse-shoed the cup. On Friday, with a chance to post a new tournament 36-hole record score, he double-bogeyed the final hole at TPC Scottsdale's Stadium Course.
Brandt Snedeker carded a 6-under 65 to move into second place at minus-18. Padraig Harrington, who is playing this event for the first time, fired a 63 to jump into a share of third place at 16-under-par 197. He was joined there by Ryan Moore, who shot 65 in round three.
Troy Matteson carded a 66 to move into fifth place at minus-15, while Brendan Steele (65) and Bill Haas (70) are one stroke back at 14-under 199.
Mickelson ran home a 21-foot birdie putt at first and seemed to be off to the races. However, he settled in with three pars in a row. At the par-4 fifth, he drained a 26-footer for birdie to move five clear of the field at 19-under.
The left-hander cruised to seven consecutive pars from the sixth. Harrington briefly inched within three, but Mickelson extended his advantage back to four with a 4-foot birdie putt at the par-5 13th.
Snedeker got within three as Mickelson parred the 14th, but it was all Mickelson from there.
At the par-5 15th, his second found a greenside bunker, but he got up and down for birdie. Mickelson stuffed his tee shot at the raucous 16th within two feet and kicked that in for birdie.
"Your adrenaline is going there so I always take five yards off the distance and I just hit a hard 9-iron. I like to hit something hard there because you feel the adrenaline there, and it turned out pretty good there," Mickelson said in a televised interview.
Mickelson kept rolling with another short birdie putt at 17. Needing birdie at the last to match the tournament's 54-hole scoring record, Mickelson hit his drive way left.
He was actually left of the pond and had a clear line to the green. Mickelson dropped his approach 15 feet from the hole and drained the birdie putt to match Calcavecchia's record of 189.
"I just took the water out of play. I just aimed right down the water and hit my driver as hard as I could. If I go left, I'm fine. If I go right, I'm fine," Mickelson explained on TV. "The tough thing for me is that new bunker that was added about five years ago up the right. That's right where my ball seems to end up and I'm trying to avoid that. I blocked it left, but you have a good angle in and given that the pin is back right tomorrow, there's a good chance I'll be there again tomorrow."
Snedeker was pretty quite early on with one birdie and seven pars through eight holes. He carded back-to-back birdies at nine and 10 to move to minus-15.
He birdied the two par-5s, 13 and 15, then carded a birdie on the 17th to get to 18-under. Snedeker was three back when he parred the last, but Mickelson caught fire down the stretch.
"It felt pretty good. Obviously, you need to shoot pretty low if you want to catch Phil right now. Anytime you shoot 6-under par you're gaining ground, unfortunately I didn't do that today on Phil," Snedeker said on TV. "Probably go out there and shoot something lower, and hope Phil doesn't have quite as good a day tomorrow."
Harrington birdied four of the first five and added a birdie on No. 8 to jump to 13-under. He wrapped birdies at 11 and 13 around a bogey on the 12th. The Irishman eagled the 15th, then parred the last three to end at 16-under.
NOTES: Mickelson's last victory was last February when he beat Tiger Woods in the final round at the Pebble Beach National Pro-Am ... Harrington's last win anywhere was at the 2008 PGA Championship ... Angel Cabrera, who hasn't won since the 2009 Masters, is tied for 12th. He is searching for his first top-10 finish since the 2011 McGladrey Classic ... A tournament record 179,022 fans attended the event on Saturday breaking the old mark of 173,210.