Bryce Harper, shown during the South Atlantic League All-Star Game on June 21, has attracted enthusiatic crowds in his first two games at Class AA Harrisburg. (Jonathan Newton/WASHINGTON POST)

They arrived several hours early at Metro Bank Park for Day 2 of Bryce Harper mania. Fans from the immediate area and from out of town gathered in front of the locked gates of the Harrisburg Senators’ stadium, making it the place to be on this early summer night just as they had on Independence Day for Harper’s Class AA debut.

When the doors opened approximately an hour before the first pitch against Erie on Tuesday night, those spectators streamed in with alacrity in anticipation of getting a glimpse of the Washington Nationals’ can’t-miss prospect in warmups. Dozens lined the railing along the right field line, focusing their gaze on the home dugout and cheering when Harper came onto the field adorn in his familiar No. 34 jersey to stretch and run lightly.

When the public address announcer called out Harper as the seventh hitter in the order, hearty applause filled the ballpark. Many snapped photos as the No. 1 overall pick in last year’s draft took his spot in left field, and because the attendance — 2,419 — for Harrisburg’s 7-3 win wasn’t nearly of the stadium-record variety on July 4 for Harper’s first game, there was plenty of elbow room in the outfield seats behind him.

One particularly devoted fan planted in the front row in left field wore a custom-ordered red Harper T-shirt with the Nationals’ curly “W” logo on the front. That souvenir wasn’t available in the team store, so others had to settle for a game program with Harper on the cover. Costing two bucks, it could become a collectible worth far more if Harper, 18, validates his considerable promise.

On a night when he went 0 for 4 at the plate and declined to speak with members of the media afterward, Harper contributed most dramatically on defense. Playing a new position, left field, he threw out two runners trying to extend singles into doubles, a reminder that his value extends well beyond his prodigious hitting. Of course he had done plenty of that in low-Class A Hagerstown, where he batted .318 with an on-base percentage of .423 and a slugging percentage of .554 with 14 home runs, 19 steals and 44 walks in 72 games to warrant a two-tier promotion, bypassing high-Class A Potomac.

“Really nice,” Senators Manager Tony Beasley said of Harper’s fielding. “He’s never been over there [in left field]. Those are different angles to set up and throw. Those throws seemed to be pretty true and on line with a lot of carry. It was impressive. Those were really, really solid throws.”

After collecting his first two hits in Class AA on Monday night before 8,092, the most ever at Metro Bank Park, Harper drove in his first run at that level in the first inning on Tuesday, although it was somewhat anticlimactic on a 1-2 groundout to second that allowed Tyler Moore to score from third. Harper did get an authoritative cut on strike two, sending SeaWolves starter Jacob Turner’s fastball sizzling foul down the first base line.

Harper recorded his first assist by getting SeaWolves first baseman Rawley Bishop in the seventh. Bishop had lined a hard shot down the third base line, and Harper delivered the strike to second baseman Josh Johnson well in advance of the sliding Bishop for the first out.

Before showing off his powerful right arm on that play, Harper had two balls hit to him in the span of three batters in the second. The first was a sacrifice fly that scored Francisco Martinez from third for Erie’s first run. The second was a two-out single off the bat of Brandon Douglas. Harper also retreated to make a catch in the third for the Senators’ second out of the inning.

In the home half of the third, Harper came to the plate with runners on second and third and none out. With the infield in, Harper took a curveball for strike one, then meekly grounded to Bishop, who looked off Moore at third before running to tag first base.

In the sixth, Harper again grounded to first, but the ball was rolling slowly enough that he was in full sprint trying to beat the throw from Bishop to Turner, who was covering the base. Harper appeared to step awkwardly as he crossed the bag, although he did not limp on his way to the dugout or in the clubhouse shortly after retiring Douglas from deep in the gap for the second out in the ninth.

“I knew he had a good arm, and I know he has showed all the skills, all the talents,” Johnson said. “But I’ve never seen it like that, and it’s extremely impressive.”