Lietzke converted a 4-foot eagle putt at the 18th hole to shoot a 6-under 66, while Purtzer two-putted from 15 feet for a birdie at the last and a 4-under 68. The pair is knotted at 11-under-par 133.
Dick Mast, who shared the first-round lead with Haas and Purtzer, bogeyed the last. He carded a 3-under 69 and is alone in fourth place at 10-under-par 134.
Mast was actually the player to move into the lead first as he tallied birdies at two, four and six. Haas matched him at two and four, but he parred six and did not draw even until the ninth. At the par-3 hole, Haas knocked a 9-iron to 8 feet and converted the birdie putt to tie for the lead.
Haas played an even better 9-iron from the fairway at 10. His ball nearly landed in the hole on the fly, but he settled for a tap-in birdie and a one- shot lead.
'That was my third 9-iron shot like that,' said Haas, referring to his approach at 10, which was a softer shot than his tee ball at nine. 'The first two were not very good.'
Haas had a decent look at birdie at the 12th, but missed his 7-footer. His cushion was padded at the hole however, as Mast missed a 4-foot par putt to fall back to 9 under par.
From that point, Haas cruised. He reached the green in two with a hybrid-club at the par-5 13th and two-putted for a birdie from 30 feet. He birdied 15 and 16 to extend his lead, but his play at the end is what truly separated him from the field.
Haas polished off four consecutive birdies with a 10-foot birdie putt at 17 and a 5-footer at the closing hole to put his name in the tournament's record books.
The 9-under-par 63 established a new course record at Augusta Pines Golf Club. Sixty-four was the previous mark which was established in 2004 by Wayne Levi, Walter Hall, Larry Nelson and Doug Tewell.
Haas' two-round total of 16-under-par 128 also set a new tournament, 36-hole record. Levi held the old mark of 131, which he set in 2004, but Larry Nelson went on to the winner's circle that year.
If Haas can hang on, it will be his fourth title of the 2006 season. He would move past Loren Roberts into first place on both the Champions Tour money list and the Charles Schwab Cup title race.
Jim Thorpe shot a 6-under 66 and is alone in fifth place at 9-under-par 135. Des Smyth, who served as one of European captain Ian Woosnam's vice captains at last month's Ryder Cup, carded a 5-under 67 and is sixth at minus-8.
Nelson (67), Ron Streck (66) and D.A. Weibring (68) are knotted in seventh place at minus-7. Mike McCullough (66), R.W. Eaks (67), Mark Johnson (67), Tom McKnight (69), Dave Eichelberger (71) and last week's SAS Championship winner Tom Jenkins (70) share 10th place at 6-under-par 138.