The brand-spanking-new Nationals Park has just about everything you could ask for in a modern ballpark.

There's a Sony Playstation Pavilion, a karaoke station, a Build-a-Bear workshop, a jungle gym and a high-definition, Jumbotron scoreboard that's billed as one of the biggest in the world.

With all those diversions, it's easy to forget Washington is the worst team in the National League, entering Friday night's game against the Cubs with 16 losses in its previous 20 games.

But the Nationals still found a way to beat the Cubs, handing them a 5-3 loss on Wil Nieves' two-run, walk-off home run off Bob Howry.

Howry replaced Carlos Marmol in the ninth of a 3-3 tie and gave up a leadoff single to Austin Kearns. After striking out Willie Harris, Howry served up the home run on an 0-2 pitch to Nieves to end a game the Cubs seemed destined to blow.

"This is a couple of games in a row where we have had opportunities and haven't taken advantage," manager Lou Piniella said. "The backup catcher got hold of a high fastball, and that was the end of it."

Piniella had the managerial wheels turning in the eighth, twice sending up pinch-hitters for a pinch-hitter, after forcing the Nationals to switch relievers.

With the Cubs trailing 3-2 and the bases loaded with one out in the eighth, Piniella sent up Daryle Ward to pinch-hit for Ronny Cedeno. Washington manager Manny Acta then opted to replace right-hander Luis Ayala with lefty Mike O'Connor.

Piniella countered with Matt Murton, who walked to force in a run and tie the game at 3-3. But Saul Rivera came on and struck out pinch-hitter Mike Fontenot before inducing Reed Johnson to end the inning with a groundout.

"We expect Fontenot to put the ball in play," Piniella said.

Piniella said he wasn't worried about using up his bench in the eighth.

"What are they there for?" he said. "To keep 'em for 14 innings. Tried to get the game over in the eighth inning. We had every chance to do it. We didn't get it done."

Earlier, Johnson made a fashion statement of sorts while making a sensational diving catch in the fifth inning to rob Felipe Lopez of an extra-base hit. Johnson's head smashed into the outfield padding in left-center field. When he got up and showed the ball to the umpires, the bill of his cap was flipped up the way Gomer Pyle wore his cap on the 1960s " Andy Griffith Show."

The crowd at Nationals Park gave Johnson a huge ovation when he left the field.

"Unbelievable," Ryan Theriot said. "That was the best play I've ever seen in person. Maybe the best play ever."

Ryan Dempster had another sharp outing. He pitched well in his fifth start, allowing two earned runs on four hits in seven innings.

Dempster served up a two-run homer to Nick Johnson in the first, then allowed only one more hit through the fifth.

Theriot's third-inning RBI double made it 2-1, but he ran the Cubs out of what could have been a big inning when he was thrown out trying to steal third with Derrek Lee at the plate and one out.

"He picked a good pitch to run on," Piniella said. "He was just thrown out. We had plenty of opportunities."

psullivan@tribune.com