Xfinity Center wasn’t supposed to be so loud at 9:30 on Tuesday night.

Maryland men’s basketball was expected to cruise past Delaware to open the season. The Terps had never lost their first home game of the season under Mark Turgeon, and the Colonial Athletic Conference’s Blue Hens — missing guard Ryan Allen, one of their best players — shouldn’t have posed much of a threat to snap that streak.

But with a minute left, after Delaware had cut what was once a 22-point Maryland lead to four, the Xfinity Center crowd felt the pressure and got louder than it had been all night.

Just as he had for the past several minutes, freshman Jalen Smith answered the call.

The forward blocked guard Kevin Anderson’s layup to prevent the Blue Hens from coming within one score, and the Terps held on the rest of the way for a 73-67 win that didn’t seem it would be nearly that close about a half-hour earlier.

“Defensively when we had to have stops, Stix stepped up and was terrific,” Turgeon said. “Double-double in his first college game.”

A few minutes earlier, when the Blue Hens came within three points and Maryland’s shooters remained ice cold, Smith made consecutive buckets to keep Delaware at bay. He blocked another shot shortly after. The McDonald’s All-American finished with a team-high 19 points and 13 rebounds, including his big plays down the stretch.

“My mood stepped up [late in the game],” Smith said, “because I was more focused.”

The Terps had distanced themselves with a 15-1 run to close the first half and carried that momentum into the second period to take a 58-36 lead about five minutes after halftime. But when Delaware switched to a zone defense, a puzzle Turgeon’s offenses have struggled to solve throughout his tenure, the Blue Hens went on a 15-2 run to narrow the scoreline.

After guard Darryl Morsell opened the game with a 3-pointer, the Terps went 1-for-8 on triples over the following nine minutes, including a handful of airballs. They missed their final 15 treys, finishing the contest 2-for-19 from distance.

“We went 2-for-[19] tonight, which probably won’t never happen again,” guard Eric Ayala said. “I’m not going to say never, but it’s not often that it happens. … Just first game stuff.”

Ayala said those struggles meant the team went inside more, and all six of his points came around the basket.

In the first half, Fernando used dunks to post 11 points and Smith controlled the offensive glass while adding nine points. But the Terps’ 44-27 halftime lead was whittled down during a five-minute second-half scoring drought.

“We let the offense affect our defense,” Turgeon said. “They made some shots, they got confident, and then we just couldn’t make a shot against the zone.”

Outside of Smith and Fernando, the Terps shot 26.8 percent from the field. Guard Anthony Cowan finished with 15 points but was 4-for-14 from the floor and 1-for-7 in the second half.

Meanwhile, Blue Hens forward Eric Carter poured in a career-high 29 points — including 10 during his team’s 15-2 run — and got Fernando into foul trouble, meaning the Angolan played just 2:17 of the final 15 minutes and was limited to 15 points and four rebounds, barely adding to his first-half totals.

That was a concerning sign for the sophomore, who was hoping to be smarter about fouling this year. But it opened the door for his fellow big man, Smith.

The Baltimore native admitted he felt “a lot of butterflies” early in his college debut, and he wasn’t perfect down the stretch, either, missing a pair of free throws that allowed the Blue Hens to hang around just a bit longer than they would’ve otherwise.

But when Xfinity Center was at its most raucous, and its most tense, he showed why he was a five-star recruit and why he remained on the floor during the tight final minute of a college debut that seemed like it was going to be a blowout a half-hour earlier.

“Being with him every day at practice and seeing him doing those things over and over, I expected him to do it in the game,” Fernando said. “I wasn’t surprised by anything he did. I knew he was going to step up anytime.”