Allen Doyle, the 2000 champion of this event paced a group of players in fourth place at 4-under-par 67. He was joined there by Brad Bryant, J.C. Snead, Keith Fergus, Morris Hatalsky, Mark Johnson, Bruce Lietzke, Mark McNulty and Lonnie Nielsen.
Morgan, who finished second at this event in 2001, got his round going with a two-putt birdie at the par-5 third. He came back to make a 15-foot birdie putt on the par-4 sixth at Newport Beach Country Club.
The 58-year-old made it two straight as his 25-foot birdie putt at the seventh found the bottom of the cup. Morgan ran off six straight pars around the turn. He moved to 4 under for his round when he birdied the par-4 14th.
Morgan then eagled the par-5 15th from 49 feet out to climb to minus-6. He parred his final three holes to hold at least a share of the first-round lead for the 28th time in his career.
'I didn't play well last week so I was a little apprehensive coming in here this week,' Morgan said. 'Not making any bogies is critical to shooting low. All in all, I played consistent.'
Levi picked up two quick birdies at the first and third. However, he gave those strokes back as he bogeyed the sixth and eighth. The 53-year-old dropped in back-to-back birdies from the ninth to get to minus-2.
After four straight pars, Levi birdied the par-5 15th. The two-time winner on the Champions Tour eagled the par-5 closing hole to share second place. Levi has now posted nine straight sub-par rounds at this tournament.
Jenkins got off to fast start with birdies at one and three. He tripped to a bogey at the sixth when he couldn't get up and down, but got that stroke back with a 15-foot birdie putt on No. 8.
On the back side, Jenkins got to 3 under with a 20-foot birdie at the 11th. He moved into a tie for second with birdies at 15 and 17.
'First hole kind of set up the round,' said Jenkins. 'I drove it well and had good feel on the greens. It is difficult to get it up and down if you start missing greens.'
Tom Purtzer, the defending champion, leads a group of eight players at 3-under-par 68. He was joined there by Jim Ahern, Ben Crenshaw, SBC Classic winner Des Smyth, Dave Eichelberger, Bruce Summerhays, Vicente Fernandez and Hale Irwin, who has already won twice this season.