ALLIANCE — It was a game of field position and opportunistic defenses.

It was a game of big plays and missed opportunities.

Top-ranked Mount Union was able to come out on the positive side in most scenarios and went on to defeat 13th-ranked Johns Hopkins 28-20 in a hard-fought semifinal game on a frigid day at Mount Union Stadium.

The undefeated Purple Raiders will make the program’s 21st appearance in the Division III national championship game — the Stagg Bowl — on Friday with the chance of winning an unprecedented 14th national championship.

The opponent will be second-ranked Mary Hardin-Baylor at 7 p.m. in Woodforest Stadium in Shenandoah, Texas.

Mount Union (14-0) has met both teams in previous late-stage playoff games over the years. The most recent came last year when the Raiders defeated Mary Hardin-Baylor 12-0 for the national championship.

Coach Vince Kehres described Saturday’s victory as a “team effort” but it was the defense that pulled off two of the biggest plays that led the Raiders to their 29th consecutive victory and a Stagg Bowl appearance for the 13th time in the past 14 years.

Senior Trevor Cox and junior Gabe Brown scored touchdowns with pass interceptions, with Brown giving his team its biggest lead of the day at 28-13 with 4:51 remaining.

Brown was able to get in front of his man while teammates Louis Berry and Andrew Roesch hammered Johns Hopkins quarterback David Tammaro.

“See ball, get ball,” Brown laughed, while describing the play. “We were in a Cover 2 and I saw the ball floating in the air. I just thought he had thrown in badly. I didn’t know he got hit.”

The two scores off interceptions gave Mount 15 defensive touchdowns on the season, which leads the nation regardless of division.

Brown, who was one of eight defenders to make six tackles or more, also was involved in the interception by Cox, which gave the Raiders a two-touchdown lead in the second quarter.

Brown tipped a pass intended for Luke McFadden and the ball deflected directly to Cox at the Mount 10-yard line and Cox had clear sailing for 90 yards. Tackle Ian McComb and linebacker Trey Williams, also part of the six-plus tackle gang, applied the pressure on Tammaro.

Johns Hopkins, making its first semifinal appearance, made the Raiders work for each of their 375 yards of offense while facing challenging field position all day.

Punter Brandon Hong-Dominquez averaged 38.4 yards on seven punts but dropped five of those punts inside the Mount 14-yard line. Mount’s average starting spot was its 24-yard line, but its first five possessions began inside its 20.

“I kept asking the defensive coaches if we were going to start every drive inside our 10,” Kehres joked.

Mount quarterback D’Angelo Fulford suffered through an uncharacteristic day as he had three passes intercepted for the first time in his three-year career. Still, he completed 12-of-23 passes for 210 yards and touchdowns of 39 and 14 yards to Justin Hill.

Sophomore running back Josh Petruccelli ran for 110 yards on 28 carries in another workhorse performance.

Johns Hopkins missed a golden opportunity in the second quarter. Harrison Wellmann returned the kickoff following Cox’s interception to the Mount 5-yard line, but an illegal blocking penalty pushed the ball back to the 20.

Mitch O’Hara sacked Tammaro for an 11-yard loss on first down and led to Johns Hopkins missing a 33-yard field-goal attempt.

“That was a huge swing,” said Kehres, who is now 25-3 in playoff games and 84-4 in his six-plus seasons.

The Blue Jays (12-2) made up for it on the next play when Jake Vall-llobera stripped Fulford from behind and Robert Fletcher scooped up the loose ball and went 25 yards for a touchdown that cut Mount’s lead to 14-6.

Tammaro completed 27-of-40 passes for 250 yards.

Johns Hopkins scored with 1:56 remaining to pull within eight points, but wide receiver Lucas Herrington caught the ensuing onside kick.