Mississippi State called a timeout, and in its huddle Coach Vic Schaefer looked at William and said, “Mo, you’re about to win the game.”
William averages only about 11 points per game, but she had awakened her scoring in the N.C.A.A. tournament. She scored 41 points in a regional final over Baylor. And she delivered again in the fevered, pressured finale of overtime on Friday.
Dillingham brought the ball up the court, then passed to William as the clock ticked down. Minutes earlier, at the end of regulation, William had driven to the basket, where her shot was blocked by UConn’s Gabby Williams. This time, William took three dribbles from near midcourt to the right of the lane, found some space and feathered a jumper over Williams as the buzzer sounded.
She opened her mouth in stunned jubilation and was mobbed on the sideline by her teammates.
“I was in shock; I’m still in shock,” William said at a postgame news conference after finishing with 13 points and 6 assists. “I’m over here like, dang, I just won the game.”
Vivians, who led the Bulldogs with 19 points but fouled out in overtime, said the victory was redemptive after a 98-38 loss to UConn in 2016. “It was personal,” she said. “We got beat by 60 last year. We had to prove that we’re a way better team than we were last year.”
The Huskies (36-1) entered the taut, thrilling game — one full of runs and lead changes and gripping suspense — with a perfect record but were not a perfect team. The top three stars from last season — Breanna Stewart, Moriah Jefferson and Morgan Tuck — were gone, chosen as the first three players in the W.N.B.A. draft.
The current UConn team was young, with Chong the only senior starter. Before this season, none of the players had been called upon to make decisive plays at pivotal moments. UConn’s depth was thin, with only two reserve players in the rotation. It lacked height inside. On Friday, the Huskies appeared disjointed and impatient, fell into some early foul trouble and trailed by 29-13 in the second quarter, their largest deficit of the season.
UConn’s vulnerabilities were exposed as it lost for the first time in nearly two and a half years, since an 88-86 defeat in overtime at Stanford on Nov. 17, 2014.
UConn rallied and persisted on Friday, as champions do, but Mississippi State’s defense pushed outward on the Huskies in a manner that was ravenous, relentless. A reliable team grew impatient and lost its composure for unusually frustrating periods. A wondrous passing team all season, the Huskies turned the ball over 17 times, collected only 11 assists and took 21 fewer shots than did the Bulldogs.
“They beat us,” Coach Geno Auriemma said. “They took us away from the things that we like to do. We didn’t have the kind of maturity that you need to win at this level at this time of the year.”
Williams, the swooping post player, kept UConn in the game with 21 points, 8 rebounds, 4 blocks and 2 steals, but the Huskies’ offense was insufficient on a rare night of poor shooting. Napheesa Collier, the country’s second-most reliable shooter, missed 7 of her 11 attempts. Kia Nurse, so dependable from the perimeter through the tournament, was 2 for 8 from the field.
“They were really aggressive,” Collier said. “We weren’t ready for it, and it put us on our heels.”
Before taking over at Mississippi State, Schaefer, as an assistant at Texas A&M, devised the suffocating pressure that helped the Aggies win the 2011 women’s N.C.A.A. title. This season, he invigorated Mississippi State’s offense by inverting his lineup, starting some reserves and putting some starters on the bench. William became a more vocal leader. And the Bulldogs have barged their way into the national championship game.
“What an unbelievable, gutsy performance that no one in the country probably thought could happen,” Schaefer said.
He added, “We beat the greatest team, with the greatest streak, in the history of sports.”
The disruption of UConn’s string of national titles may be brief. Another long winning streak could begin in November.
Four starters return, and next year’s roster will include 6-foot-6 forward Azura Stevens, a transfer from Duke who was an all-Atlantic Coast Conference player. Also joining is Megan Walker, a 6-foot-1 guard from Virginia, who was recently named the national high school player of the year.
But on Friday the possibility of future renewal was no balm for present disappointment. For one rare night, UConn was only second best.
“When you get to this point in the season and you lose,” Auriemma said, “it’s the worst feeling imaginable.”