Nationals starting pitcher Stephen Strasburg makes his first start of the season against the New York Mets on Thursday. (Jonathan Newton/The Washington Post)

Thursday afternoon’s game between the New York Mets and the Washington Nationals was supposed to be the best pitching matchup of the young baseball season. The Mets’ Matt Harvey, making his first start in 20 months, was facing Stephen Strasburg, the Nationals’ opening day starter the past three seasons. Two-thirds full Nationals Park on a gloomy April afternoon seemed an unfit stage for such theater.

As it was, there was hardly any drama to the Mets’ 6-3 win: Harvey dominated, and Strasburg — undone by bad bounces, bad fielding and bad luck — did not.

Harvey, a young, powerful right-hander nicknamed “The Dark Knight,” had not pitched in the majors in 593 days. Tommy John surgery in October 2013 slowed his meteoric trajectory, but the 2013 all-star relaunched Thursday with six impressive scoreless innings.

“He’s always good. I mean, taking a year off, it’s just a setback he had,” Nationals right fielder Bryce Harper said. “But of course, he’s gonna come back and do what he does.”

On the other side was Strasburg, displaced from his opening day role by the arrival of Max Scherzer. If he felt he had something to prove, perhaps he had gotten the better assignment anyway: The matchup with Harvey was a heavyweight bout.

Nationals beat writer Chelsea Janes talks about the three areas of concern for the World Series favorites ahead of the team's season opener against the New York Mets on April 5. (Jayne W. Orenstein/The Washington Post)

But Strasburg stumbled in the third inning. He allowed a single to Curtis Granderson with one out before his defense let him down. He got David Wright to hit a would-be double-play ball to shortstop. Ian Desmond’s approach left him an in-between hop that he could not handle. Just like that, inning over became two on with one out.

“I’m all for owning up when I make a mistake,” Desmond said. “I wish I would’ve put myself in a better position to — I don’t really know — get a better hop. I wasn’t expecting the ball to bounce up like that. But like I said, the object is to convert the balls that are rolling into outs. I wasn’t able to do that.”

His third error of the season gave the Mets two men on and led to three unearned runs. The Nationals allowed six such runs in this opening series, all of them the result of errors by Desmond, who has made at least seven errors in each of his past two Aprils.

“I don’t know,” Manager Matt Williams said when asked to explain the April troubles. “As a whole, he’s a pretty darn good player. We’re happy to have him on our club.”

After Desmond’s error, luck abandoned Strasburg. In the midst of what became a four-hit, four-run third inning, the Mets hit one ball hard. David Murphy chopped a base hit toward first base that never reached the infield dirt but sat instead in Ryan Zimmerman’s glove, too far from first to be helpful. Travis d’Arnaud blooped a base hit to center field to drive in two runs.

“I don’t think anything went wrong if you look at the contact that they made. It was a lot of very weak contact,” said Strasburg, whose final line included nine hits, three walks and three earned runs.

“That’s just how baseball is sometimes. You make good pitches, and they hit it where we’re not.”

Had his command been sharper, had his defense held, had soft liners found gloves instead of grass, Strasburg still might not have matched Harvey.

The 26-year-old dominated using a 97-mph fastball, a curveball and a change-up, his repertoire well honed despite not pitching in a game since Aug. 24, 2013. He struck out nine Nationals and walked one.

Harper entered the game 4 for 7 — he had been seeing the ball well, taking controlled swings and making consistent contact. On Thursday, he struck out three times, waiting for the fastball yet still unable to hit it despite his most violent hacks. He struck out on 97-mph fastballs each time.

“I keep saying it. I’ve said it a million times: He’s going to be Cy Young one day, and everybody knows that,” Harper said. “He’s one of the toughest at-bats I’ve ever had.”

Harvey was held to a pitch count and made it through six innings on 91 pitches. By then, the damage of that third inning was too much to repair.

Without injured outfielders Denard Span and Jayson Werth and Silver Slugging third baseman Anthony Rendon, the Nationals’ lineup figured to be less formidable than it might otherwise be. When opportunities to score emerged, they had to take them. Through the first two games of the season, the offense had squandered all of them. In 11 at-bats with runners in scoring position, the Nationals had no hits.

In the second inning Thursday, with Desmond on second after his first hit of the season, Uggla hit a groundball to deep third and beat it out with a headfirst slide to first. Desmond did not score. So the Nationals’ first hit with a runner in scoring position did not yield a run.

The next one did. Taylor smacked a line-drive double off the left-center field wall to drive home two runs. The fill-in leadoff man has hit safely in all three games this season. A pinch-hit single by Reed Johnson added the third run.

Since Stephen Strasburg came up in 2010, the Nationals have scored three runs for him in 50 of his starts. They have lost seven of those games, this one because of unfavorable bounces and a Mets ace returned to form.