Jayson Werth smacks a single in his first at-bat since May 6. (Ricky Carioti/The Washington Post)

A familiar face — scruffy beard, long hair and all — appeared in Thursday’s lineup. He stood in center field at Nationals Park. He soaked up the ovation as his name was announced for the first time in nearly three months. He yukked it up with umpires between innings. He stood on the steps of the dugout, this time with a batting helmet, gloves and a bat. Jayson Werth was back, and he was happy.

In a rare sight for this remarkable Washington Nationals season, nearly all of their important pieces took the field on Thursday. Werth stood between Bryce Harper and Michael Morse in the outfield. Ryan Zimmerman tossed balls across the diamond to Adam LaRoche. And in a 3-0 win over the Philadelphia Phillies, it showed.

“We’re getting there,” Manager Davey Johnson said. “This is the closest we’ve been in a long time.”

Zimmerman returned after a balky back that held him out of the previous two starting lineups.

LaRoche, the consistent force who helped carry the offense through all its nicks and lows, drilled a towering home run and drove in another run.

Starter Ross Detwiler delivered his most dominant performance of the season, a dazzling seven innings to maintain the Nationals’ 21 / 2 game lead over the Atlanta Braves in the National League East.

And Werth smacked a single and drove in a run in his first game back from wrist surgery.

At first, Werth seemed destined for a return later this week after a few more minor league rehab games. But even before playing for Class A Potomac on Wednesday, he knew he was in good enough shape to rejoin his major league teammates. He called General Manager Mike Rizzo, who passed the word along to Johnson. By the next day, the outfielder was back in a game at Nationals Park.

“It was good,” Werth said of his time in the minors before deadpanning: “Those minor league fields were kind of spongy so it was good to get back on a hard surface.”

Werth said it was by chance that he returned in time to face the Phillies, his former team. Starting on the mound Thursday for Philadelphia: left-hander Cole Hamels, who was at the center of an eventful game between the teams on May 6, when Werth broke his wrist diving for a line drive.

“He’s a leader for us, and especially against his old team,” Detwiler said of Werth. “He always seems to do just a little more against them.”

The crowd, still trickling into the stadium before the game, cheered as Werth’s name was announced and his face appeared on the scoreboard as part of the starting lineup. In his first at-bat, he fouled off three pitches before hitting a single to left field.

As he took a turn around first base, he smacked his white-gloved hands together.

From the dugout, Chad Tracy, who rehabbed with Werth in Class AAA Syracuse, raised his arms in the air in celebration. On the bench, Zimmerman mimicked the motion as Mark DeRosa laughed.

Werth’s return changes not only the dynamic in the clubhouse but on the field. Of the right-handed outfielders on the team, he’s the most reliable and experienced defender. Mostly used in right field, he played center on Thursday — his manager to referred to him as a “6-foot-6 donkey” out there — allowing Harper to rest his legs in right field.

Werth also guided a ball to second base for a groundout with two runners on in the third inning, enough to drive in a run that gave Washington a 2-0 lead. Yet most of the night’s power came from LaRoche, one of the team’s guiding forces this season through its injuries and offensive droughts.

At the plate, LaRoche looks laid-back, standing straight-legged and rocking his arms. When the ball approaches, he turns and drives his legs and bat through the strike zone.

LaRoche drilled the first pitch he saw from Hamels in the second inning just like that, a monstrous solo shot into the second deck in right field.

It was his 20th home run of the season, the seventh time in his career he has reached that milestone. The Nationals’ leading run producer added two singles and another RBI, his 64th of the season, most among NL first baseman.

Detwiler held down the Phillies; he gave up only three hits on 88 pitches over seven innings. He worked quickly and efficiently, a trait he learned from his stint in the bullpen earlier this season. He retired the last 14 batters he faced and leaned on his fastball, throwing it 70-plus times. He used his biting power sinker to net 11 groundouts.

“That’s just some awfully good stuff,” Johnson said. “And he’s starting to realize that.”

Detwiler benefited from a strong throw from Harper and quick tag by catcher Sandy Leon that gunned down a potential run at home plate in the second inning.

Detwiler could have pitched longer. But Johnson realizes Detwiler is young and with more experience will use him deeper in games. So far, however, Detwiler has quickly shown that he’s maturing and developing gradually with each start.

But the night belonged to the near-whole Nationals roster and its wild-haired outfielder Werth, who was back for the rest of this season’s pennant race.

“Like I never missed a step really,” he said.