SAN ANTONIO -- Western Washington warded off a major upset with an 80-76 overtime victory against the Nova Southeastern Sharks on Tuesday at the NCAA Division II Women's Basketball Championship quarterfinals.

Western Washington (29-4) willl take on the winner of second-ranked Ashland, last year's runner-up, and Gannon in Wednesday's semifinals at 9:30 p.m. ET at Bill Greehey Arena. Augustana (S.D.) meets Dowling in the opening semifinal at 7 p.m. Nova Southeastern completed its season with a 23-9 record.

Senior center Britt Harris put the Vikings up for good (76-74) with a layup at the 31-second mark in the overtime period. Harris was fouled in the act of shooting, and made the ensuing free throw. Senior guard Corinn Waltrip made one of two free throws and Western Washington led 78-74. The Sharks' junior guard Jessica Russi kept it close with a layup with 10 seconds left. Waltrip was fouled and sank both free throws with nine seconds remaining as the Vikings won 80-76.

"I am really proud of these women sitting beside me," Western Washington coach Carmen Dolfo said. "We really fought hard. I think we got a bit on our heels in the second half. They were so excited about being in overtime. We run the five-minute overtime in practice. I just felt confidence from them. We did it together, and we did it with great will."

Dolfo is in her 22nd season at the Vikings helm. She guided her team to the 2000 NCAA semifinals, where Western Washington lost 80-74 to eventual national champion Northern Kentucky.

Harris recorded a double-double in the game, pouring in 24 points (9 of 12 shooting) and grabbing 10 rebounds. Waltrip added 21points, hitting 8 of 11 from the floor, and shelling out six assists.

The Vikings seemed to be cruising to another berth in the semifinals, as they led 42-29 at halftime after shooting 68 percent from the field. Western Washington led by as much as 17 points (40-23) with 1:13 left in the opening stanza.

But Nova Southeastern, which lost in the first round of the 2008 playoffs (its only other tournament appearance), took a 64-62 lead with 4:05 remaining in regulation. The Sharks outscored their opponent 35-20 to take the brief lead, but Harris tied the score with a layup at the 3:45 mark. Harris then hit another bucket as the Vikings led 64-66 at 3:09. Meixandra Porter tied the game at 66 and Amanda Burakoski gave Nova Southeastern a 68-66 lead at 1:33. Waltrip's jumper with nine seconds left tied the matchup at 68.

"We know when things go wrong, we can't get down on ourselves," said Harris, who scored nine of Western Washington's 12 points in overtime. "We just have to keep fighing. We believe in each other, and we believe in what we do, to get back back on track."

Junior forward Sarah Hill added 10 points and accounted for seven rebounds for the Vikings.

"We have been through too much this season to have surrendered," Hill said. "And we said, 'No, We are not going to be done here. We have other business.'"

Four Shark players scored in double figures, led by senior guard Tailor Jones' 20 points and 11 rebounds. Sophomore guard Danielle Robinson contributed 18 points, Burakoski scored 16 and Porter had 15.

Western Washington shot 55.2 percent (32-for-58) and Nova Southeastern hit 40.3 percent (29-for-72). The Vikings held a 41-31 lead in total rebounds.