Wayne Levi and Gary Koch each carded rounds of 3-under-par 67 in the second round and are tied for third place at 5-under-par 135 at The Moors Golf Club.
For the second day, heavy wind made play difficult but not as difficult for Morgan. The 23-time winner on the Champions Tour grew up in Oklahoma and has more experience playing in the windy conditions.
'I don't like playing in the wind, obviously, but maybe I've had a little more experience from a career standpoint than some of the players have,' said Morgan, who won this year's SBC Classic and is the elder circuit's leading money winner.
Morgan, who titled here in 2000, started the second round a stroke behind Fuzzy Zoeller. He wasted little time in getting into the lead as he birdied the first, but his play later on the front nine kept him on top of the leaderboard.
Morgan birdied three holes in a row from the sixth, but dropped a shot at the ninth. Jenkins moved up the leaderboard with five birdies in his first 13 holes, but Morgan answered once again.
The 57-year-old birdied the par-4 13th and parred out to take a one-stroke lead into the final round.
Before Morgan's march to the winner's circle, he will have to go through Jenkins, a four-time champion on the 50-and-over tour. Jenkins failed to make a birdie after 13 and knows he'll have a challenge in front of him if he is to win for the first time since last year's Bruno's Memorial Classic.
'With his shot-making ability, he drives the ball so straight and solid that the wind doesn't really affect him,' Jenkins said, referring to the second- round leader. 'It's just like a rifle when he hits it, just straight as a string.'
Mark Lye (66), Dana Quigley (67), Rodger Davis (68), Mike McCullough (68), Tom Purtzer (68), Howard Twitty (68) and Zoeller (71) share fifth place at 4-under-par 136.
Bob Gilder, the defending champion who was tied with Morgan a stroke behind Zoeller, struggled on Saturday. He bogeyed the first three holes and never recovered, shooting a 3-over-par 73. Gilder is tied for 29th place at 1-under-par 139.