Lehman's 36-hole total tied the tour record set by Tiger Woods at the 2000 NEC Invitational.
Couples, winless since 1998, added a 64 to his opening round 63, but had to settle for second place at 127. Couples played the TPC at the Canyons on Thursday in the event's three-course rotation. That course is a par 71 while the other two courses played in the tournament have a par of 72.
Daly also played the Canyons and shot a 62 to put himself alone in third at 129. Daly has three top-four finishes during the last five weeks, including a victory at the European Tour's BMW International.
The cut will be made after Friday's third round.
Lehman picked up where he left off Wednesday, rolling in 10 birdies at the Southern Highlands olf Club. He opened the event with a 63 at the TPC-Summerlin.
"The expectations were high coming in here," said Lehman, who is winless since January 2000 and has missed three straight cuts. "The clubs feel comfortable in my hands."
This is Lehman's first appearance since, and he is making the most of it. Through two rounds, he has 19 birdies and no bogeys.
"I am playing the way I was hoping to play," said Lehman, who is 36th on the money list, six spots away from qualifying for the Tour Championship. "To shoot these kinds of scores makes me real happy."