Lehman did not make a bogey at the Shoal Creek Country Club in the first major championship of the year on the Champions circuit. He shot a 5-under 67 to finish the day a stroke in front of Mark Calcavecchia, Nick Price, Wayne Levi and Chien Soon Lu.
Jay Haas, whose son Bill had the lead on the regular PGA Tour after one round of the Wells Fargo Championship in Charlotte, N.C., was alone in sixth after firing a 69.
Lehman, who won the British Open 15 years ago, has four victories on the Champions Tour since turning 50 in 2009 and two of those wins have come this year. He leads the tour's 2011 money list.
"I like the no bogeys," said Lehman, who captured last year's Senior PGA Championship. "No matter what I shoot, if I play bogey-free I'm usually pretty happy."