The swing took place when Lietzke was at 17 and with McCord playing the 16th in the group behind. Lietzke knocked his tee shot 12 feet from the hole at the par-3 17th and watched his ball drop into the left side of the cup to make birdie and match McCord at 8-under-par.
McCord, who took the one-shot lead with a 10-foot birdie putt from the fringe at the 15th, drove into the right rough at 16. His second shot missed the green short and right and his chip on to the green was less than spectacular, stopping 15 feet from the hole. McCord missed the par save left to fall one behind Lietzke with two holes to play.
Lietzke nearly dropped his swinging 20-foot birdie try in the side of the cup at 18, but settled for par and a one-shot clubhouse lead. McCord stiffed his tee ball seven feet from the stick at No. 17 but his bid to tie Lietzke for the lead fell one foot short of the hole.
McCord, making his first start of the season after weeks of broadcasting for CBS, nailed a 3-wood down the fairway at 18 but he left himself with a length to the hole that was in between clubs. He went with the less-lofted club and it did not work out, pushing his approach 65 feet right of the hole.
McCord gave it a run but missed short, giving Lietzke his first title of 2002.
'It was a great weekend,' said Lietzke, who finished 66-67. 'The golf course played into my hands when the wind quit blowing this weekend. I started hitting it close and made some putts. It worked on the weekend.'
Ed Dougherty and Bruce Fleisher occupied the top spots on the leaderboard heading into the final round but back-nine bogeys cost them dearly.
Dougherty, the overnight leader, dropped shots at 12 and 13 to fall out of contention while Fleisher was in position to capture the title until bogeys at the Club de Golf Chapultepec's final two par-3s, the 13th and 17th, also cost Fleisher a chance at his 15th Senior Tour victory.
McCord grabbed the lead around the turn thanks to a 60-foot, left-to-right eagle putt at No. 8. He added birdies at nine and 11 to extend the lead but he let the field back in the tournament at 12 when he missed a seven-foot par save.
Lietzke started to claw into the tournament on the front nine with birdies at four and eight but he drew within one of McCord with a 12-foot birdie putt at the 11th. He played a gorgeous iron shot into the 12th green that stopped two feet from the hole and when McCord bogeyed the 12th, Lietzke was tied for the lead.
Lietzke has his opportunities to pull away from McCord, first at the 13th when his tee shot landed 10 feet short of the hole. His birdie try targeted the hole but turned right at the last second, costing Lietzke a birdie and a one-shot lead.
At 15, Lietzke hit a beautiful pitch over trees for his third from the right rough that came to rest six feet from the hole. Once again failed to capitalize, leaving the green with a five but he remained tied for the lead in the championship after the unlikely par.
'I couldn't have made a par going low,' said Lietzke, referring to his options from the rough at 15. 'All of a sudden there was an opening real high that I didn't see the first time. I was trying to get it 15 feet, but I hit it six feet.
'Maybe the moral there is to take a little extra time and check all of your options. I found the option there that allowed me to make a par and keep my momentum.'
It was his birdie at 17, coupled with McCord's mistake at 16 that gave Lietzke his third title on the Senior Tour and the $255,000 first-prize check.
McCord finished with a 69 in his bid for his third Senior Tour title and his first since the 1999 Senior Tour Championship.
Irwin once again snuck up on the field on Sunday. He reached 5-under-par before he dropped a shot at the par-3 13th but rebounded with back-to-back birdies at 14 and 15.
Irwin missed an eight-foot birdie putt that would have tied him for the lead at 16 but after Lietzke went to 8-under, Irwin could not get closer. He ran home a 10-foot birdie at 17 and had a final chance at reaching 8-under on the 18th.
The three-time U.S. Open champion left himself only six feet but his putt missed right at the end and instead gave Irwin his second runner-up finish this season.
'I'm not getting off to that good start and I just put myself in such a position to crawl back so far,' said Irwin, who lost by one stroke to Doug Tewell last week at the Verizon Classic. 'I hit a good putt at the last hole. That's the nature of the game.'
Irwin finished with a five-under 67.
Full-field scores from the Audi Senior Classic