The 50-year-old played a flawless round of golf with no bogeys and six birdies, including two over the final two holes to secure his second win since joining the tour three months ago.
'I had a great putting tournament,' said Lietzke. 'This is a very nice event.'
His first-place prize of $240,000 moved him from 28th to 17th on the 2001 money list giving him a total of $813,600, just over $100,000 more than his best year on the PGA Tour.
Lietzke held off a late surge by McCord (67) to secure the win. McCord tied Lietzke on the par-5 17th with his last of a stretch of three consecutive birdies before stepping onto the 18th.
The Senior Tour rookie played his approach shot on No. 17 to within 20 feet. He two-putted for birdie to regain the lead.
'I was thinking I needed to eagle 17,' Lietzke said. 'I anticipated 18 being an eagle hole and thought Gary would make birdie there.'
McCord bogeyed the 18th to finish at 12-under 204 thus granting the victory to Lietzke, who sealed it by holing a 20-foot putt for birdie on the final hole.
'I never looked at the leaderboard,' said McCord. 'I thought if I shot 65 I'd be at 14-under and be right in it. I gave myself a lot of chances out there, made some and some I didn't.'
Doyle began his round with a bogey on the par-4 2nd but was perfect from that point on, making seven birdies without dropping a shot. His round of six-under 66 mimicked that of Lietzke and gave him his 22nd top-10 finish this year.
Bobby Wadkins, Lietzke's playing partner and long-time friend, finished four strokes off the lead at 11-under 205 alongside Doug Tewell. Wadkins extended his streak of rounds under-par to 18.
Jim Thorpe, who had won two consecutive events coming into the weekend, failed to extend his streak of victories to three. His final-round score of 8-under 64 was the tournament's best.
Larry Nelson was two-under for the day after coming into the round trailing Lietzke by only one shot. He finished at 10-under 206, five shots off lead.
Mark McCumber, who made his debut on the Senior Tour this weekend, posted a final round score of 74 to finish at one-under 215.
Full-field scores from the SAS Championship