Haas shot his second 63 in four days to move to 26-under-par 262, one stroke clear of Kenny Perry and Cameron Beckman.
Perry, the 1995 Hope winner, tied a career best with a 10-under 62 Saturday at the Arnold Palmer Private Course at PGA West, site of Sundays final round. Beckman shot an eight-birdie, one-bogey 65 at Indian Wells.
This is the first time in more than five years that the 48-year-old Haas has led heading into the final round. He was tied at the top through 54 holes of the 1996 National Car Rental Classic, but shot a Sunday 71 to tie for fifth behind winner Tiger Woods.
Haas also led through four rounds when he won this event in 1988; though, this year hes already exceeded that 22-under winning total.
I still think somewhere in the mid-30s (under par) is probably what its going to take to win, he said. Somebody could come out of the pack at 23- or 24-under ' its funny to say thats the pack, but it is here.
Haas, playing Indian Wells, started the day two off the lead, and quickly made ground by holing an 8-iron out of a divot in the rough from 150 yards on the par-4 first. He went on to add eight birdies ' four over his final five holes ' and one bogey to his card.
Thats always nice to hole a shot for eagle at any point, but to do it to start the round ' that a bonus, said Haas, who has nine career PGA Tour titles, but none since the 1993 Texas Open.
Overnight co-leaders Kirk Triplett and Deane Pappas are now two off the pace after a pair of 67s, tied for fourth place with Brandel Chamblee (66) and David Berganio, Jr. (64).
The third of the third-round leaders, Duffy Waldorf, is a shot further removed following a 68. Last weeks winner Jerry Kelly (68) and Phil Mickelson (65) are a distant four shots back.
News, Notes and Numbers
*The cutline fell at 12-under-par 276. Joe Durant, who set a 90-hole tour scoring record in winning this event a year ago, missed the cut. Durant shot even-par 72 Saturday to finish at 10-under-par.
*Seventy-seven players made the cut. The final round will be played with threesomes starting on both the front and back nines at PGA West. No amateurs will be competing.
Full-field scores from the Bob Hope Chrysler Classic