Gonzaga's stranglehold on the West Coast Conference tournament had been especially frustrating for Saint Mary's, with the Gaels often seeing their nemesis celebrate at their expense.
Not Tuesday night.
No. 21 Saint Mary's led the WCC championship game nearly the entire way to beat No. 17 Gonzaga 69-60 behind Aidan Mahaney's 23 points and Mitchell Saxen's 19 points and 15 rebounds.
Gonzaga (25-7) had won four WCC championships in a row and 10 of 11, with Saint Mary's in 2019 the one year the Bulldogs didn't claim the trophy.
The Gaels (26-7) earned the conference's automatic bid for the NCAA tournament, but both sides were certain to make the 68-team field even before tipoff.
"We beat a good team, a program we've got a ton of respect for," Saint Mary's coach Randy Bennett said. "They've helped us become the program that we are because we were punching up there for a long time and trying to do what they were doing and be as good as they were."
The sharp-shooting Mahaney was a major reason the Gaels prevailed. He made 9 of 15 shots, including 5 of 7 from 3-point range. And Saxen produced a double-double despite battling foul trouble.
Saxen said he maintained his aggressiveness by "playing to the emotions of the game."
"It's hard to tone it down in the championship game like that," he explained. "Got in foul trouble. I should've been smart early and stayed down on my feet on a couple of plays."
WCC player of the year Augustas Marciulionis scored 13 points for St. Mary's and was named the tournament's most outstanding player.
Anton Watson led the Zags with 18 points. Ryan Nembhard finished with 13 points and 11 assists for Gonzaga, and Graham Ike had 10 points even though he played only 20 minutes because of foul trouble.
"We've got a lot to work on on this loss," Watson said. "We're looking forward to the tournament and trying to make some noise there. We can't hang our heads on this."
The contest was close throughout -- Saint Mary's largest lead was 11 points -- but the Gaels managed to stay in front almost the whole way. Gonzaga used an eight-point run to finally take the lead with 7:41 left, but that advantage lasted only 22 seconds and was answered with a seven-point spurt from the Gaels.
Both teams came in surging. Saint Mary's now has won 23 of 25 games, and the Gaels ended Gonzaga's nine-game winning streak while holding the Bulldogs to a season-low 60 points. All this after the Gaels began the season 3-5.
"It wasn't just one moment," Mahaney said of Saint Mary's turnaround. "We just kept chipping and chipping and chipping and chipping until eventually we broke through. It's not easy. It's a credit to everyone just believing."
The Gaels also, at least briefly, ended the Bulldogs' domination of this series. Gonzaga had won 26 of the past 32 meetings and had been the Gaels' nemesis in WCC championship games by winning three of the previous four against Saint Mary's.
The Associated Press contributed to this report.