He took advantage of a teammate's screen and hit a long-range jumper of his own to give the defending 1A boys basketball state champs a two-point lead in the game's expiring seconds.
"He's clutch," said head coach Eric Jessen after the Mustangs' 55-53 first-round win over a tough Eagle squad. "That's why we wanted Kace to have the basketball. ... He's spent a lot of time with the basketball. He wants the ball at the end of the game."
Roundy's confidence was critical as the Mustangs overcame a slow start thanks to the stifling Eagle defense.
Duchesne also rebounded well throughout the game, which meant a single try for Bryce Valley on each offensive outing down the floor most of the time.
"We weren't able to get anything going," said Jessen. "We weren't executing.."
Part of the problem for the Mustangs was those first-day state tournament jitters. With only two returning starters, most of the men on the floor were new to the pressure of the playoffs.
"We missed some jump shots early and part of that was nerves," he said.
But another component of their offensive struggles was the stellar defense of Duchesne.
"Most of it boiled down to how well Duchesne defended us," said Jessen. "We felt they did a really good job against us."
Jessen said they specifically addressed the need to box out and grab rebounds in pregame plans.
"That's one of the things we talked about," he said. "But Duchesne is so athletic; they jump well; they have good length. That caused us fits."
The Eagles were led by Macoy Young, who played huge in the contest on both ends of the court. He finished with 16 points, including three 3-point baskets. Thomas added 11 points and Shiaba Allen finished with 12 points.
Roundy, a four-year starter, finished with 21 points, while teammate Jake Pearson added 12 points in the win. The Mustangs will face Liahona in the second round of the tournament at the Sevier Valley Center this afternoon.