Isao Aoki and Tom Kite share fourth place at 7-under-par 137 with Steve Veriato one shot further back.
Jenkins began his day five shots off Allen Doyle's pace. He started his climb up the leaderboard with back-to-back birdies from the third. Jenkins, who is a three-time winner on the Champions Tour, went on to birdie the par-4 eighth to make the turn at minus-5 for the tournament.
Jenkins started his back nine with a birdie at the par-4 10th. However, he gave that stroke back with a bogey at the next.
The University of Houston alum moved to 5-under for his round with a birdie at the par-3 14th. Jenkins went on to close out his round with back-to-back birdies from the 17th to grab a share of the lead.
Lietzke, who came from behind to win last year's title, had the lead to himself until he found trouble at the 18th.
On the closing hole, he dumped one shot in the water and also had to blast out from a buried lie in a bunker. He triple-bogeyed the hole to fall into a share of the lead.
'I played 17 holes like Tiger Woods and the 18th hole like my grandmother,' said Lietzke.
He birdied three straight holes from the third to get to minus-8 and around the turn, he kept that going with birdies at Nos. 10 and 12.
Lietzke extended his lead with birdies at 15 and 17 to move to 12-under for the tournament before the mishap at 18.
'That was a really great round other than the last hole,' said Lietzke, who is trying to be the first Champions Tour player since Hale Irwin to successfully defend a title.
Irwin accomplished that at the Turtle Bay Championship last fall.
Darcy, who is making his Champions Tour debut, started his round with three straight pars. He then birdied the par-4 fourth from four feet. Darcy later rolled in a 40-footer for birdie at the seventh and a 20-footer at the ninth to make the turn at eight-under.
The Irishman notched consecutive birdies starting with a 15-footer at the 13th to move to the top of the leaderboard at minus-10. However, Darcy faltered down the stretch with a bogey at the 18th, when he was unable to get up-and-down from a bunker, to fall into a share of the lead.
'I played pretty solid for 17 holes until the 18th,' said Darcy. 'I'm struggling a little bit with my irons.'
The long-time European Tour player is pleased to be near the top in his first event on the Champions Tour.
'I'm surprised a little where I am because this is my first event,' Darcy said. 'I've played very little golf since last October. I am very happy where I am.'
Irwin, Seiji Ebihara, David Eger, Walter Hall and Bobby Walzel share seventh place at 5-under-par 139.
Jim Thorpe withdrew from the tournament after an incident in Mexico City Friday evening. Thorpe was among a group of six golfers and two caddies that were out to dinner at a local restaurant. While they were dining, the men were robbed at gun point. Some wrist watches and other personal items were taken.