WASHINGTON — Nationals Park had quite an opening.

Ryan Zimmerman hit a tiebreaking homer off Peter Moylan with two outs in the ninth inning, and the Washington Nationals beat the Atlanta Braves 3-2 Sunday night in the first regular-season game at the $611 million stadium.

With the dome of the U.S. Capitol lit up against the black night sky beyond left field, and the Washington Monument visible from patches of the upper deck, Zimmerman raised his right fist as he rounded first base. Teammates spilled out of the dugout — it’s along the first-base line now, not the third-base line, like at old RFK Stadium — and greeted the face of the franchise at home plate for celebratory pounds on the back.

Twenty-four straight Washington batters had made out before the home run — Washington’s fourth hit of the game and first since the first inning.

Nick Johnson delivered an RBI double in his first at-bat in more than 18 months, Odalis Perez matched Tim Hudson, and Jon Rauch (1-0) earned the victory after blowing a save in the top of the ninth.

All in all, it sent the paid crowd of 39,389 heading away with even more to smile about than the gleaming white-stone-and-glass ballpark.

With President Bush on hand to throw out the ceremonial first pitch, the Nationals had their first victory in a season opener in four tries since moving to the nation’s capital from Montreal.

Zimmerman was larger than life as he rounded the bases, then came out of the dugout for a curtain call — it all was shown on the 4,500-plus square foot high-definition video board above right-center, the most immediately noticeable perk of the new digs. It’s about three times larger than the scoreboard at creaky, leaky RFK, a remnant from the 1960s that was the Nationals’ home from 2005-07.

"We’ve waited for so long for a place that can be our own," Zimmerman said. "There are just too many people on this team that are tired of being mediocre."

The Nationals were one out from the victory, ahead 2-1 in the ninth. But Rauch was pressed into closing duty because Chad Cordero has right shoulder tendinitis, and the tying run scored on a passed ball charged to Paul Lo Duca, signed during the offseason as a free agent.

It was a couple of holdovers who drove in Washington’s runs, both in the first inning. Johnson, who missed all of 2007 with a broken leg, provided an RBI double, sliding into second as if he’d never been away. Johnson then slid again, as if for emphasis, when he scored on Austin Kearns’ single.

After that, Hudson was perfect. He retired his last 19 batters, departing after allowing three hits over seven innings. Perhaps surprisingly, Perez was Hudson’s equal. A left-hander signed in mid-February to a minor league deal, Perez gave up one run in five innings — on Chipper Jones’ solo homer in the fourth.

The Braves boasted their own, more modest, debut Sunday: alternate road uniforms. The navy blue caps with a white "A," and navy jerseys with a white, script "Atlanta" on the chest represent the first change to the team’s away getup since 1987.

Everywhere else one looked, there was a curly "W" — on the red hats Nationals players and so many fans wore, at the center of the giant clock attached to the main scoreboard, etched into the grass in center field, carved into the dirt at the back of the pitcher’s mound.

Those were the least of the differences between the team’s old home and its new one.

"You just can’t compare it," Nationals manager Manny Acta said. "It’s top-of-the-line. It’s exciting to come to work every day here."

Fans arrived as early as 6 a.m. to buy $5 upper-deck tickets, and there were no apparent transportation problems, with about 50 buses lined up for the free, 10-minute shuttle service from parking lots at RFK. The Nationals encouraged fans to arrive early, and they did. At one gate, there was a line three blocks long, but police redirected those spectators elsewhere, and the place was pretty close to full when President Bush strode to the mound in a red Nationals warmup jacket to renew an old baseball tradition.

Greeted by a fugue of cheers and jeers, Bush — former owner of the Texas Rangers — threw the ceremonial first pitch to Acta.

The Braves took the unusual step of taking full infield and outfield practice before the game, aiming to learn the ins and outs of the place.

To a man, Nationals players have said they haven’t had time to learn all of the quirks of their new digs, yet right fielder Kearns contributed a nice play in the second inning, turning Brian McCann’s single into an out at second. Kearns perfectly played the carom off the bullpen wall, turned and made a throw to second baseman Ronnie Belliard, who relayed the ball to shortstop Cristian Guzman, who tagged out McCann.

The next inning, the Braves collected their second hit of the season — and followed it up with their second baserunning gaffe of the season. This time, it was Kelly Johnson who singled to center, then was caught stealing.Notes: Nationals president Stan Kasten said the team has sold about 18,000 season tickets, more than in 2007, but fewer than in 2005, the team’s first season in the city. ... After years of wearing "C. Jones" on the back of his Braves jersey — because Andruw Jones, now with the Dodgers, was a teammate — Chipper Jones was identified Sunday simply as "Jones." ... Nationals LF Elijah Dukes left with a tight right hamstring after grounding out in the fifth.