USC led twice by seven points early in the second half Saturday, but eventually withered under Louisiana Tech's pressure defense in a 75-66 loss in the final of the women's Mideast Regional.
Debra Williams scored 26 points as fourth-seeded Louisiana Tech (30-3) earned a trip to the Final Four for the first time since since 1990. The Lady Techsters have won 24 in a row since a 34-point loss to Tennessee in December.
Southern Cal (26-4), which hasn't been to the Final Four since 1986, suffered several turnovers and the Lady Techsters pulled even at 45 on consecutive baskets by LaShawn Brown.
Amy Brown's three-point play put Tech ahead to stay, 55-54, with 12:21 to play. Williams' rebound basket and three-pointer gave Tech some breathing room, 64-58.
Nicky McCrimmon's driving layup cut it to 64-61, but Williams responded from the outside. Racquel Spurlock came up with a steal that resulted in a seven-point lead, and Southern Cal never got closer than five points the rest of the way.
Southern Cal appeared tired down the stretch. Lisa Leslie, the Pac-10's all-time leading scorer and rebounder, was short on a free throw, short from in close and missed badly on two three-pointer attempts in the final minutes.
She finished with 24 points, while Tina Thompson scored 17 and McCrimmon 16.
Pam Thomas had 16 points for Louisiana Tech.
The game was tied 12 times in the first half, the last time at 27, before the Lady Techsters scored five consecutive points, the last two coming on Vickie Johnson's steal and basket.
But Southern Cal scored the final six points of the half. Thompson's two free throws started the run, and then Tracy Atwater got loose inside. Jody Anton's 15-footer with three seconds left gave Southern Cal a 37-34 halftime lead.
Leslie and McCrimmon opened the second half with baskets to move Southern Cal out front 41-34.