Quarterback C.J. Brown rushes for a touchdown during the Terps’ 47-10 win over Old Dominion on Sept. 7, 2013.

C.J. Brown floated a high, arcing pass to the back corner of the end zone late in the third quarter of Saturday’s Terrapins football game against Old Dominion. Wide receiver Stefon Diggs tracked it and leapt, but the pass was just out of his reach and sailed harmlessly out of bounds.

As Diggs went to stop, though, an Old Dominion defensive back fell on top of him and rolled up on his right leg. Diggs slid to a stop, face down on the Byrd Stadium turf and lay motionless for several seconds as athletic trainers rushed to him. A hush fell over the crowd.

But just as quickly as he went down, Diggs popped right back up, gave a triumphant fist pump and ran back to the Terps bench. He was all right. The star sophomore wouldn’t play another down after the scary moment, though the damage against the Monarchs had already been done.

The Terps offense rolled again Saturday afternoon with a 47-10 victory over Old Dominion before an announced 38,377 at Byrd Stadium.

Diggs set a career high with 179 receiving yards on six catches including one touchdown. Running back Brandon Ross gained a career-high 149 yards on 18 carries and scored one touchdown. And the Terps defense held Old Dominion to 335 total yards for a dominant performance against the Norfolk, Va., school transitioning from the Football Championship Subdivision to the Football Bowl Subdivision.

“It’s awesome,” defensive end Roman Braglio said. “It’s great watching the offense just run down there and kick butt out on the field. The crowd goes crazy every time we score and it’s great atmosphere.”

The Terps again posted a big first half, taking a 31-3 lead into the break. Both Ross and Diggs had gained more than 100 yards in the first two quarters, and the defense picked off Monarchs quarterback and Walter Payton Award winner Taylor Heinicke three times. Any questions about the Terps being able to keep up with a fast-paced, high-flying Old Dominion offense were answered.

The teams traded field goals to start the game, but the Terps offense would score 42 straight points to shut the door on the Monarchs. First, Ross rushed in from five yards out, capping a seven-play, 77-yard drive in which the running back gained 49 of those yards himself.

Less than three minutes later, the Terps displayed their quick strike potential. After safety Sean Davis intercepted Heinicke and returned the ball to the Monarchs 31-yard line — a 15-yard penalty put the ball back on the 46 — Brown found Diggs down the middle for a diving 41-yard catch to advance to the five. Then Brown took it himself through the left side for his third rushing score of the year.

After linebacker Yannick Ngakoue intercepted Heinicke at the Terps 3-yard line in the first drive of the second quarter, Brown drove the Terps 97 yards to put them ahead 24-3. On a first and 10 from the Old Dominion 41, Brown tossed the ball out to Diggs in the flat, and the speedster stiff-armed a defender, dashed down the sideline and high-stepped before somersaulting into the end zone with his second touchdown of the year.

“I had some good blocks on the outside by [wide receiver] Nigel [King] and [tight end Dave Stinebaugh],” Diggs said. “They sealed their guys. C.J. gave me a good ball. From that point out, I was just trying to get in the end zone. I dove a little bit because I wasn’t sure I was going to get there all the way. Luckily, I got there. I was just happy that I got there.”

There was no looking back from there. Backup running back Albert Reid would score from 27 yards out for the final touchdown of the first half for a 31-3 lead at the intermission.

It was more of the same in the third quarter. Brown scored another rushing touchdown with a 31-yard run through the right side. He broke a tackle and juked out a defender on his way to the score.

Brown finished the game 14-of-22 for 275 yards and two touchdowns through the air, and he also rushed four times for 36 yards and two touchdowns. He’s accounted for nine touchdowns through the Terps’ first two games.

“The biggest thing is I’m just more confident in the offense so I know where the ball needs to go and my feet are more set to where I believe the ball should go and I’m able to read the defense,” Brown said. [Offensive coordinator Mike Locksley] has done a great job helping me out with mechanics and timing and footwork. And it’s all coming together on the field.”

The first-team offense’s final touchdown came just one play after Diggs was shaken up. Brown found wide receiver Nigel King on the right side from four yards out. It capped an 11-play, 60-yard drive that ate 4:56 off the clock — the Terps’ longest scoring drive of the day in terms of time.

The Terps defense got into the scoring act to open the fourth quarter, too, tackling a Monarchs wide receiver in the end zone for a safety after the Monarchs tried to run on a bubble screen from their own 1-yard line.

The Monarchs would score on a 13-play, 61-yard drive against the Terps reserves to make the score 47-10 with five minutes remaining in the game.

The Terps have aced their first two tests of the season, defeating Florida International and Old Dominion by a combined 88-20 score. But next week the Terps travel to Hartford, Conn., to take on Connecticut in coach Randy Edsall’s first return to his former school. The Huskies got the better of the Terps last year, but Edsall said Saturday night was all about the win over the Monarchs.

“We’ll address all that I’m sure this week,” Edsall said. “But I want to enjoy this one. Wins are hard to come by. I want to enjoy this one.”