Riverside Academy’s Cinderella run in the Division III playoffs had to end at some point.

The Rebels’ (9-10-3) run ended on Monday as they fell to district rival University Lab 5-0 in the quarterfinals after pulling out a pair of surprising upsets in the previous two rounds in what was the first playoff appearance in school history.

“Nobody expected us to be where we are,” Riverside coach Jonathan Reed said. “This was a rebuilding year, this was a foundation year and to be in the quarterfinals, it’s one heck of a feeling just to be here.”

U-High coach Chris Mitchell said the game plan was to score early in order to break up the momentum Riverside had built up the past few weeks.

That’s exactly what the Cubs did, scoring twice in the first 10 minutes of the match.

Senior Thomas Kobetz opened the scoring in the fifth minute when he knocked a ball from point-blank range off the cross from forward Maddy Vick.

The Cubs followed up just five minutes later when Miguel Vilas sent a ball into the back post, where a sprinting Scot McKenzie headed the ball into the net.

The final score of the half came in the 23rd minute when defender Ben Smith ripped a no-look, turnaround volley from 10 yards out — all but sealing the end of the Riverside run.

“We went into the game with a defensive mindset that we were going to hold these guys out and we knew we had to play defensive soccer,” Reed said. “They capitalized on some of our mistakes and put two quick into the goal.”

Headers in the box were the difference maker in the match as the Cubs produced three such goals, including two in the second half.

Junior defender John Kurpius flicked a Major Mittendorf free kick into the net late in the game for the fourth goal of the day, while Grant Smith — typically a keeper for U-High — got in on the action with a header stemming from a free kick on the final play of the game.

By the end of 80 minutes, U-High outshot the Rebels 18-4 despite resting several key players in the second half, including Kobetz and Vilas.

“We just stressed that we wanted to start fast , jump on them early and that way we could get those guys out of the game early, which we were able to do,” Mitchell said. “We want to not have any injuries and preserve our players because we know the semifinals are going to be a completely different story.”