West Virginia scored with just 88 seconds remaining in regulation to knock off No. 7 Oklahoma State 1-0 on Sunday in Morgantown.
OSU All-American goalie AD Franch recorded a season-high seven saves but couldn't stop the shot of WVU's Frances Silva at the 88:32 mark as the Cowgirls dropped their first-ever contest against the Mountaineers and suffered a second-straight defeat for the first time since 2010.
Playing without injured starters Kristen Kelley and Miriam Rhinehart, OSU was shut out for just the second time this season as the defending Big 12 champions fell to 9-3-0 and 0-2-0 in conference play.
In an evenly played first half, the Mountaineers owned an 8-7 edge on shots, with both teams recording a pair of saves.
WVU had a couple of scoring chances from close range in the 18th minute, but the Cowgirl defense rose to the occasion, blocking one of the shots and clearing another off the line, to keep the Mountaineers off the scoreboard. And OSU got a standout play from Hayley McKinney when the sophomore defender made a sliding tackle to deny Kelsie Maloney of a shot opportunity in the 25th minute.
Franch also came up big, making a spectacular leaping save at the 33:07 mark on a seven-yard shot by Maloney.
In the opening minute of the second half, the Cowgirls narrowly missed falling behind as two deep shots by WVU both caromed off the crossbar, the first a left-footed chance by Bry McCarthy and the second by Silva.
Franch once again saved the Cowgirls in the 77th minute, this time diving and extending her left arm to deflect a shot by Maloney for another save.
In the 81st minute, OSU created a chance when Megan Marchesano sent a cross into the box, but George Christie's header sailed a few feet above the crossbar.
The match appeared destined for overtime until Silva won the ball near midfield with just under two minutes remaining, then beat her defender and delivered a shot from the top of the box past Franch for the game winner.
OSU returns on Friday at 7 p.m. when the Cowgirls host Iowa State before a Sunday night Bedlam showdown with Oklahoma.