The final-hole birdie gave Lehman a 1-under 71 for the day, pulling him into a tie with Jay Don Blake (70) at 6-under 210.
Saturday proved to be rough for second-round leader Fred Couples, who fell into a tie for third place at minus-4 with a round of 3-over 75. Couples notched three birdies, four bogeys and one double-bogey
Knotted with Couples in third were Mark O'Meara (67) and Mike Goodes (70).
Chien Soon Lu, who had a share of first place after a birdie on the seventh hole, ended with four bogeys on the back nine to card a 1-over 73, ending at minus-3 along with Dan Forsman (69) and Chip Beck (71).