Murray (14-2-2), which had allowed just 11 goals all season entering the game, became the third region champion ousted from the topsy-turvy 4A bracket. Both Ogden and Provo bowed out in the opening round.
Mountain View (13-4-2), the second seed from Region 7, advanced to meet either Maple Mountain or Alta in Tuesday's semifinals. The Bruins last reached the state final in 2011.
"Our biggest goal was to outhustle them," Mountain View coach Jace Green said. "I always say, 'Win the ball, win the game,' and we did so.
"We didn't have a ton of waves of offense, but we didn't need it. We played scrappy and we just worked hard."
Defender Kade Hernandez started the scoring in the 39th minute when he got his foot on a corner kick. It capped a frustrating first half for the Bruins, who played directly into a steady and pounding wind for the first 40 minutes.
"Having the wind going against us in the first half got in our heads that we needed to hold them and stay tight," the junior said. "Then in the second half, we'd just go at it."
Hernandez's biggest play, though, was a sliding save in the 62nd minute on an Eric Lovell shot with Mountain View goalkeeper Zac Bryant out of the goal.
At the time, it preserved a 2-0 lead the Bruins built 10 minutes earlier when VandenBos banged home a rebound of Elder Aguayo's shot.
Mountain View's two goals matched the most Murray had given up in a game this season. The Spartans' previous loss came March 25 against Skyline.
Mountain View 2, Murray 1
R Kade Hernandez and Ryan VandenBos score goals as the Bruins became just the third team to score multiple times against Murray this season.
• Aaron Gannon scores in the 69th minute for the Spartans, who became the third region champ to lose in the tournament.
• Mountain View reaches the 4A semifinals for the first time since back-to-back appearances in 2011 and 2012.