Jerry McGee, Isao Aoki, Seiji Ebihara and Bruce Fleisher share fourth place at 4-under 68, while Bruce Summerhays, Howard Twitty, Danny Edwards, David Eger and Joe Inman are one shot further back at minus-3.
Doyle started out hot on the front nine. He posted three consecutive birdies starting at the third to quickly move to 3-under. The seven-time winner on the Champions Tour notched back-to-back birdies from the seventh en route to a 5-under on the front side.
'I had a good start to my round,' said Doyle. 'There was no wind when we started, which helped.'
On the back side, Doyle continued his hot play when he rolled in an eagle putt at the par-5 12th. Doyle briefly climbed to 8-under with a birdie at the 16th, but faltered with a bogey at the par-5 18th.
'All in all, I had a very good day today,' said Doyle, whose 65 tied the lowest first round in tournament history. 'I am pleased. The leader is under great pressure. You get everyone trying to catch you.'
Darcy, who was in the first group to tee off on the back nine, had an up-and-down back side. He started with a birdie at the par-4 10th, but faltered with a bogey at the next. The Irishman came right back with a birdie at the par-5 12th.
Darcy, who is making his Champions Tour debut, moved to 2-under with a birdie at the 14th. He dropped a shot at the following hole, but again recovered with a birdie at the next to make the turn at minus-2.
On the front side, Darcy was more consistent in his play. He parred the first two holes, then notched a birdie at the par-4 third. After a series of pars, Darcy closed his round with back-to-back birdies from the eighth to get to 5-under.
Lietzke, who erased a five-shot deficit entering the final round to win this event last year, stumbled out of the gate with a bogey at the 10th, his first hole. He recovered quickly with a birdie at the 12th, before carding consecutive birdies from the 14th.
The three-time winner last season dropped another shot with a bogey at the 16th. Lietzke was able to recover that shot with a birdie at the 18th to make the turn at minus-2.
On the front side, Lietzke birdied the second and then the fourth. He collected his final birdie of the round at the par-5 sixth.
Bobby Walzel, Hale Irwin, Tom Jenkins, John Mahaffey, Graham Marsh and Fuzzy Zoeller share 13th place at 2-under 70.
Vicente Fernandez withdrew before the start of the tournament because of back spasms.