Baylor was nearly halfway there.
With three seconds on the clock, Brittney Griner's fadeaway from the left baseline bounced off the front of the rim, and a few of the Stanford Cardinal began to jump around in jubilation.
Chiney Ogwumike secured the rebound and a 71-69 win for the fourth-ranked Cardinal over No. 1 Baylor in a rematch of last year's Final Four, ending the Lady Bears' 42-game winning streak.
Baylor's 42-game run ranked fifth on the NCAA Division 1 women's basketball all-time winning streak list, 48 behind Connecticut's staggering 90-game stretch between 2008-11.
It was Baylor's first loss since falling to Texas A&M in the regional finals of the 2011 NCAA Tournament.
Ogumike, who had 18 points, drove past Griner before her reverse layup over the outstretched arms of the reigning player of the year went down and gave the Cardinal (3-0) a 70-66 lead with 22 seconds left.
Destiny Williams' 3-pointer at the other end cut the deficit to one with 10 ticks to go. Toni Kokenis split a pair from the line and Baylor (2-1) snatched the rebound before calling a timeout at midcourt to set up the final play.
Baylor downed Stanford, 59-47, in Denver en route to a national championship back in April.
The Lady Bears, who became the first NCAA collegiate basketball team, male or female, to finish with a perfect 40-0 mark last year, joined seven other unbeaten NCAA women's champions.
Stanford led by as many as 14 in the opening half before taking a 31-29 edge into the locker room.
The Lady Bears lost All-American guard Odyssey Sims early on in the contest due to a strained hamstring.
Griner tallied 18 of her 22 points in the second half in defeat.