URBANA, Ill. -- Ellen Tsay outlasted Gabriella DeSimone 5-7, 7-5, 6-3 on court five, providing the clincher in No. 12-seeded Stanford's 4-3 victory against No. 5-seeded USC in a match that lasted exactly five hours on Friday in the Round of 16 at the NCAA championships.

Stanford (19-4, 8-2 Pac-12) entered the match facing a clear obstacle. Pac-12 champion USC (23-3, 9-0 Pac-12) notched a 6-1 victory back on March 30 and eliminated the Cardinal from last year's postseason in the quarterfinals.

Taking the court nearly two hours after its original start of 1 p.m. ET, Stanford was up to the task. The Cardinal became the first team this season to snag the doubles point from USC, taking a 1-0 lead.

After Natalie Dillon and Krista Hardebeck coasted to an 8-1 rout on court three, USC evened things up with an 8-6 victory at the No. 2 spot.

The deciding doubles match was a rollercoaster on court one between the No. 8-ranked duo of Kristie Ahn and Nicole Gibbs against USC's No. 2-ranked pair of Kaitlyn Christian and Sabrina Santamaria. Ahn and Gibbs trailed 4-1, stormed back to lead 7-4, only to then fall behind 8-7. However, Ahn and Gibbs bounced back for what would be a 9-8 (2) victory.

Stacey Tan followed with a 6-2, 6-2 victory against Giuliana Olmos at the No. 4 spot, putting Stanford in front 2-0.

USC registered its first point at the No. 6 position when Kaitlyn Christian put away Natalie Dillon 6-3, 6-1, trimming the deficit to 2-1.

Stanford then received a boost at the top of the lineup when Gibbs suddenly reversed her match against USC's Santamaria, ranked No. 2 in the country. Santamaria led 5-1 and 6-5 in the first set before Gibbs came all the way back for a 7-6 (3) win and ultimately rode that momentum to a 6-2 win in the second frame.

The Trojans received a 6-3, 7-6 (5) triumph from Zoe Scandalis on court three and a 6-4, 2-6, 7-5 nail-biter from Danielle Lao at the No. 2 spot.

That left the match riding on court five, where DeSimone and Tsay had already traded 7-5 victories. Tied at three in the final set, Tsay ripped off three consecutive games for the win.

Stanford next faces No. 4 Georgia on Sunday in the quarterfinals.