Inside the clubhouse, watching the first inning on television, relievers Drew Storen and Tyler Clippard could hear Bryce Harper’s name rumble over the Nationals Park speakers. They listened to the accompanying roar, the crowd frothing for Harper’s first at-bat of the season. The moment reduced Storen to a daydreamer, same as the 45,274 souls wearing red and packing the seats. He leaned over and asked Clippard: “Can you imagine if he hits a home run right now?”

“It would be like that perfect thing to happen,” Clippard said later. “But it doesn’t ever happen, right?”

If the next six months unfold like the Nationals’ 2-0, opening day victory over the Miami Marlins, Washington’s 2013 season may be an exercise in imagination. Try to think of the perfect thing to happen. And then, if form from Game 1 holds, double it.

Can you imagine? On his first opening day, Harper blasted a home run in each of his first two at-bats. Stephen Strasburg, the Nationals’ other first overall pick, used his powerful efficiency for seven shutout innings, in which he allowed three hits and no walks, needing only 80 pitches before Manager Davey Johnson pulled him.

Monday began with a celebration of what the Nationals accomplished last season, the revealing of a division title banner and passing out individual trophies. What came after the first pitch stretched the limits of what may happen this season, a fever dream for longtime followers who endured 100-loss seasons and waited until now, their twin forces at last together for a full season.

“You just shake your head,” new Nationals center fielder Denard Span said. “You shake your head in amazement.”

In his first at-bat of the season, Harper pulverized a hanging curveball and sent a 385-foot declaration of his intentions throttling to right field. In his first start of a season without a team-imposed innings limit, Strasburg retired 19 consecutive batters following a single to lead off the game. Before the afternoon ended, gray clouds having replaced bright sun, Harper heard a smattering of “M-V-P” chants and Strasburg had barely broken a sweat. Harper is 20; Strasburg is 24.

“They’re both just scratching the surface,” shortstop Ian Desmond said. “They’ve got a lot more epic things in them.”

They had help. Third baseman Ryan Zimmerman’s brilliant, diving play to end the first inning saved a run and started Strasburg rolling. Once Johnson gave Strasburg a quick hook — denying him a first-ever chance to pitch into the eighth inning — the Nationals’ bullpen preserved the shutout. Clippard fired a scoreless eighth before Rafael Soriano, the $14 million closer the Nationals signed as a free agent, recorded his first save.

Mostly, the Nationals leaned on their phenoms. Harper came to the plate in the first inning with two outs and no one on base. Ricky Nolasco started him with a splitter, an 82-mph pitch Harper regarded with indifference as it dropped out of the strike zone. Nolasco then threw a sweeping, 73-mph curveball, trying to curl over a breaking ball for strike one when most hitters would expect a fastball.

When Nolasco tried the curve, Harper lashed at the ball, all controlled violence, and smashed a laser toward right field. Giancarlo Stanton sprinted to the warning track and stared up at the ball as a fan — impersonating Jayson Werth in both full uniform and facial hair — snagged it with a glove. The park — and the clubhouse — was frenzied.

“If you see a veteran do that, you’re like, ‘That’s really impressive,’ ” Storen said. “Breaking ball, 1-0, to a lefty? In the first inning? He’s not a 20-year-old. He doesn’t look like one. And he doesn’t play like one.”

When Harper crossed home plate, he pointed to his parents, a retired ironworker named Ron and a paralegal named Sheri, sitting behind home plate. He slapped high-fives with teammates. Zimmerman told him, “Calm down. You don’t have to hit me so hard.”

The Nationals did not manage another hit off Nolasco, long their nemesis, until Harper’s next at bat. He battled to a full count, and Nolasco, out of pitches to show him after Harper took a 2-2 splitter, settled on a 3-2 slider. Harper unloaded, taking a split-second to admire his bolt. The ball sailed 10 rows deep.

A small group chanted, “M-V-P!” The crowd would not cease cheering or sit down. Harper asked veteran Chad Tracy if he should hop out of the dugout for a curtain call. “I don’t think he even waited for an answer,” Tracy said.

Zimmerman stepped out of the batter’s box. Harper took his curtain call, waving his hand over his head.

Strasburg continued to slice through the Marlins, using his power sinker, which reached 98 mph, and his breaking pitches to keep them off balance and rolling grounders — 10 in all. Johnson worried the festivities of the occasion had “drained” his starter.

“If it wasn’t opening day or the first start of the year, it would have been a different story,” Strasburg said.

In the one moment Strasburg fell into trouble, Harper found himself in the middle of things. In the seventh inning, Stanton and Placido Polanco ripped consecutive one-out hits to put runners on the corners. Rob Brantly followed with a fly ball to left.

Harper settled under the ball as Stanton readied at third base. He snagged the ball while charging forward and unleashed a wicked throw. Stanton, smartly, stayed at third. The throw drew an ovation — and maybe a little scorn from the dugout. Johnson would have preferred Harper hit the cutoff man.

“I’m going to try to throw everybody out,” Harper said.

Said Johnson: “It’s hard for me to figure what’s going on in his mind. I know he’s always full bore.”

Polanco, perhaps anticipating Stanton to run home, drifted off first base. Catcher Wilson Ramos held the ball, waiting for Polanco to retreat. Ramos fired to first baseman Adam LaRoche, who trapped Polanco by firing to Danny Espinosa. Stanton raced for home, and Espinosa turned and fired home to nab him, Ramos making a nifty tag.

“Just kind of hung him out to dry,” LaRoche said.

Soriano ended it with a professional, dominant save, whiffing Stanton flailing at a breaking ball in the dirt, and the Nationals lined up and shook hands. The 2012 National League East championship banner loomed behind them. Just to the right, four flags flew. Three of them were adorned with seasons in which Washington won the pennant.

The fourth was blank. But you could use your imagination.

“I think the perfect formula,” Harper said later, “would be a World Series win.”