Haas completed 54 holes at 14-under-par 202. His third-round 63 tied Jim Thorpe's course record from 2003. Bob Charles, Jay Sigel and Bruce Lietzke also carded 63s in this event, but they came on three courses other than Sonoma Golf Club, this week's host venue.
He was joined there by Tom Kite (68), Tom Watson (69), Lonnie Nielsen (70) and Loren Roberts (70).
Mark McNulty, the defending champion, also had a solid day as he fired a 7-under 65 to move into a share of seventh place at minus-7. He was joined there by Gil Morgan, who had shared the second-round lead with Nielsen and Roberts.
Haas was on fire early during Saturday's round. The 51-year-old opened with a birdie on the second and made it two in a row as he birdied the third as well.
The nine-time winner on the PGA Tour got to 8 under with an 10-foot birdie putt on the fourth, which gave him a one-shot lead. Haas extended that lead as he sank a 6-foot birdie try at the fifth.
Haas cooled off with four straight pars from the sixth. Around the turn, he converted consecutive birdies from the 10th to climb to 11 under.
The Wake Forest alum birdied the par-5 13th for the second round in a row. Haas poured in birdie putts on 16 and 17 to get to 14 under and a six-stroke cushion.
'I'm going to try to take [the final round] as any other round,' said Haas, who has two Champions Tour wins. 'Obviously I will have a lot of pressure on me. Everybody will be firing at me and there are some great names on that leaderboard behind me. Obviously if I can shoot that round (today), any of those guys can too.'
Quigley played his first eight holes at plus-1 with a bogey on the fifth, but he caught fire around the turn. The 58-year-old holed out for eagle on the ninth, then birdied No. 10 to quickly get to 6 under.
The 10-time winner on the Champions Tour bogeyed the 11th, but came right back with a birdie on 12. Quigley birdied 16 and 17 to share second place.
'I would have felt good if I was a couple shots better, but I'm happy,' said Quigley. 'I think I'm in pretty good shape on the money list, but I'm not sure about the Schwab Cup yet. There will be pressure on a lot of guys on Sunday. There's a lot of money out there.'
Kite had grabbed the early lead at 7 under with three straight birdies to open his round. He gave one stroke back with a bogey on five. The 55-year-old wrapped birdies at 11 and 13 around a bogey on No. 12. His birdie on the 16th got him to minus-8.
Watson played the first 15 holes at even-par with three birdies and three bogeys. The 2000 and 2002 champion here eagled 15 and birdied 16 to get to 8 under.
Nielsen birdied the second to go with eight pars on his opening nine holes. He stumbled to a bogey at the 10th, but moved into a share of second with birdies on the 13th and 16th.
Roberts birdied the seventh and 10th to climb to minus-8. He picked up another birdie on the par-5 16th. However, he bogeyed the last to slide back into a share of second.
Morris Hatalsky, Tom Purtzer and Craig Stadler share ninth place at 5-under-par 211. Mark James is one stroke behind that trio at minus-4.