The Rockets asserted themselves early and led 19-12 after the first quarter.
"We did a really good job coming out of the gates, played hard and knocked some shots down," R-U head coach Steve Neuberger said.
After an evenly matched second period, R-U took a 35-28 lead into halftime.
Things got even more interesting as St. Mary's outscored R-U by three points in the third quarter, narrowing the score to 42-38.
"We got a little stagnant and weren't moving around as much as we should have," Neuberger said. "St. Mary's was playing pretty solid defense, especially in those two quarters, and kept it close."
The Hawks even managed to briefly tie the game during the fourth quarter, but the Rockets quickly regained the lead and did not let go until the end.
"We were able to hit some big shots and our defense stepped up in the fourth quarter to limit their shots," Neuberger said. "We got some key free throws down the stretch and were lucky enough to come out on top."
R-U junior Tanner Hilbrands led his team offensively with 23 points. He also racked up four rebounds and five steals on defense.
"He (Tanner) had a really good night for us," Neuberger said. "He makes good aggressive moves to the basket and he was able to get to the foul line quite a bit Friday night. Defensively, too, he played an outstanding game and got some big rebounds for us."
Senior Cam Kuchel contributed 10 points and three assists. On the defensive end, senior Andrew Hagert led his team with nine rebounds.
Despite the loss, St. Mary's head coach Scott Ruden said he was very satisfied with his team's performance.
"Our effort was fantastic," Ruden said. "It was probably the best game my kids have played all year. R-U has a very talented team and you can tell by our records that we're probably not their caliber, but we gave them a run for their money. We grew a lot in that game."
Junior Matt Wesselmann led the Hawks in scoring with 14 points, followed by senior Tyler Delperdang with 10 and senior Nate Roder with nine. Freshman Brady Harpenau contributed a team-high seven assists.
Defensively, freshman Ethan Biezuns recorded eight rebounds for St. Mary's, followed by Roder with seven.
"It was a real team effort," Ruden summarized his team's performance.
R-U improved to 11-2 overall while St. Mary's dropped to 3-8. Both teams are optimistic about their upcoming games.
The Rockets travel down Highway 3 to face Akron-Westfield on Tuesday.
"We're going to play well," Neuberger said. "Hopefully we can come out with the same intensity we showed in the fourth quarter Friday night. Hopefully that will carry over for our next game."
The Hawks face off with MMC on Friday.
"We're coming into a part of our schedule where we're going to be able to compete again," Ruden said. "We're optimistic that we're going to finish on a strong note."