Purtzer shot a bogey-free 10-under 62 on Friday to take the first-round lead in the Champions Tour's season-opening MasterCard Championship.
'It helped my confidence,' Purtzer said. 'When you take three months off, you're not really sure how things are going to go. A round like today does a lot.'
Jim Thorpe, who tied for second last year and is coming off a victory at the season-ending Charles Schwab Cup Championship, was a stroke back along with playing partner Allen Doyle.
Purtzer was strong off the tees, hit all 18 greens in regulation and putted just 28 times. His 62 was a stroke shy of the course record set by Loren Roberts when he won in 2006. It was Purtzer's 13th under-par round at Hualalai, where he finished fifth in his 2004 debut and ninth the following year.
The 56-year-old Purtzer birdied three of the first six holes and made a 15-foot eagle putt on the 551-yard seventh that was set up by a stunning shot with a rescue club. He made birdie putts inside 8 feet on Nos. 9-11, 13 and 15 to reach 10 under.
'That helps my scoring average a little bit. If I could just stop right now,' said Purtzer, seeking his fifth Champions Tour title.
Last year, he beat Roberts in a four-hole playoff at the AT&T Champions Classic and finished a career-best eighth on the money list.
The players tore through the meticulous, oceanside layout in calm conditions and slightly overcast skies that hid the peak of Mount Hualalai and provided a little relief from the sun.
'It was another day in paradise,' said D.A. Weibring, who opened with a 64.
Weibring finished tied for seventh last year and tied for third in 2006.
'Two years ago here, I shot a 20-under without making a bogey and didn't win,' he said. 'That's not going to happen too many times.'
Purtzer said scoring conditions were perfect.
'When you get a golf course in as good as shape as this one is, the scores are going to be low,' he said. 'Everything about the golf course is as good as it can be.'
He said his round is surprising because he had to take four days off last week after getting a cortisone shot in his left elbow. He sneaked in some putting and chipping practice, which paid off Friday.
Thorpe tied Purtzer for the lead momentarily. Thorpe hit a knockdown 7-iron to set up his 6-foot birdie on No. 16 that moved him to 10 under, but lost a stroke on the next hole when his tee shot from 164 yards found the lava rocks on the right side.
Thorpe, who is seeking to extend his win-streak to nine straight seasons, said he'll need at least seven birdies a day to be in contention.
'We know the scores are going to be low, so you have to constantly make birdies,' Thorpe said.
The group at 65 included John Harris, Mark McNulty, Eduardo Romero, Mark Wiebe and Jay Haas, seeking an unprecedented third straight player of the year award.
Jerry Pate, Bob Gilder, John Jacobs, Bernhard Langer, Brad Bryant, Tom Watson and Tom Jenkins shot 66s. Pate struggled early and made the turn at 37 but carded a 29 on the back nine.
Defending champion Hale Irwin struggled and was tied for 36th in the elite 41-player field. The 62-year-old star, who skipped Thursday's pro-am for personal reasons, was at 72, which snapped his streak of 12 straight rounds in the 60s.
Last year, Irwin won the winners-only tournament, beating Thorpe and Tom Kite by five strokes for his tour-record 45th victory. Irwin closed with a 65 for a 23-under 193 total.
Bobby Wadkins and Peter Jacobsen opened with 73s and were the only players above par. The field averaged 67.53 strokes on the Jack Nicklaus-designed course.