Before Maryland baseball’s pivotal series against Nebraska, left fielder Marty Costes said he looked forward to the atmosphere at Haymarket Park.

The junior hasn’t always shown the caliber of play this year that led him to be selected in the 25th round of the 2017 MLB Draft. But on Friday, in front of an announced crowd of 5,343, he seemed to recapture the All-Big Ten form he had last season as he led Maryland to a 15-7 win.

In the first inning, Costes powered a 2-0 pitch from starter Matt Waldron to deep right-center field, rounding the bases with his head down as his solo home run gave the Terps an early lead.

Two innings later, Costes went yard again, with a markedly different reaction — he skipped out of the batter’s box, glanced at the Maryland dugout as he dropped his bat and turned to watch as kids in the outfield grass section chased his shot.

Costes said he feels the Terps plays better when their backs are against the wall. His 4-for-4, five-RBI performance illustrated that he — and the rest of the team — could overcome the pressure surrounding must-win Big Ten games.

“I know I love playing in this park,” Costes said. “The atmosphere and the crowd, it was just a beautiful day and for baseball in general. So fortunately I was able to produce for the team and you know, they play well behind me.”

The Terps’ first series-opening win since March 2 put another game between them and the Cornhuskers in the Big Ten standings — and brought Maryland one game closer to conference tournament contention.

After Costes’ homer in the opening frame, Maryland (20-25, 6-9 Big Ten) added two more runs in the second on right fielder Randy Bednar’s RBI double and first baseman Justin Morris’ sacrifice fly.

Costes is no stranger to hitting homers against Nebraska (20-23, 4-10). He launched one to left field last year over bathrooms positioned about 20 feet past the foul pole. Nebraska Coach Darin Erstad told the Big Ten Network during an in-game interview that Waldron hadn’t established his inside fastball to that point. He left a fastball over the plate in the first at-bat and hung a curveball for the second one.

“I got back to my old self a little bit,” Costes said. “Stance-wise, doing what I was doing a little bit freshman year. Recognizing that sometimes as a player, you’ve got to look back to when you were the best of yourself.”

Waldron (5-3, 4.26 ERA) recovered in the middle innings — after Costes’ second homer, he retired the next eight batters before pitching around Costes in the sixth. Designated hitter Will Watson followed up the walk with a hit-by-pitch, and center fielder Zach Jancarski’s sacrifice bunt advanced them to second and third.

When third baseman Taylor Wright hit a ground ball, second baseman Zac Repinski fielded it and threw home, but the errant toss got past catcher Jesse Wilkening, and two runs scored to widen Maryland’s advantage to 6-2. The groan that reverberated around Haymarket Park following the miscue may have epitomized some of the frustration surrounding the Cornhuskers this season.

In the seventh, an RBI triple from second baseman Nick Dunn and an RBI single from Costes preceded Wright’s three-run homer, which established an 11-2 edge — Maryland’s first game in double digits since March 21. Starter Mark DiLuia (2-4, 5.40 ERA) supplied six innings and surrendered two runs in his third Friday start.

“Marty was unbelievable tonight,” coach Rob Vaughn said. “I don’t think he hit a ball less than 120 miles an hour tonight. So, he was obviously very, very good. And it was kind of a complete effort. We had guys up and down the lineup contributing.”

A four-run eighth gave the Terps a cushion for when right-handers Ryan Hill and Mike Vasturia scuffled, showing signs of the inconsistency that has marred the Terps’ bullpen this year. Hill allowed two runs in the seventh and loaded the bases in the eighth, before Vasturia entered to strand all three Cornhuskers. In the ninth, Vasturia surrendered a three-run homer to third baseman Luke Roskam to make it 15-7.

Still, Nebraska couldn’t overcome the Terps’ offensive onslaught. As the fans dispersed and the outs mounted against the home team, Maryland appeared to have the mettle to withstand the stress around critical contests.

That’s a good sign for the Terps, who will have nothing but must-win games for their last eight regular-season Big Ten matchups.

“It’s been an up-and-down year for us,” Costes said. “But it’s all about how you finish. We have a shot, and it’s good to have a shot at least.”