WASHINGTON - With one strike to go Sunday, the visiting fans that commandeered Nationals Park roared as the Phillies players and coaches perked up in the dugout. The reward for enduring 5 hours and 50 minutes worth of rain delays in a span of four days was one strike away. Antonio Bastardo was the pitcher who would throw that strike, as good as any guarantee in baseball this season.

"Sometimes we miss a pitch," Bastardo said later, after the Phillies had lost, 5-4, to the Washington Nationals in 10 innings.

No, these players are not robots, and even the ones who most resemble out-making machines can be disrupted. A week ago, the Phillies had lost only one game all season in which they led after eight innings. In the last six games, they have suffered three such defeats.

"Unfortunately," Roy Halladay said, "a lot of times in baseball, it happens in spurts."

First, Halladay's day was trimmed to five innings when Mother Nature intervened with a rainstorm that caused a 1-hour, 11-minute delay. It was the second straight time rain affected a Halladay start, and the third time in four days the Phillies bullpen was forced to do the heavy lifting.

Then, still grasping a lead with two outs in the ninth inning, Bastardo threw a slider that did not bite like so many of his nasty pitches have in this glorious season.

Before facing Ian Desmond, Bastardo had faced 116 righthanded batters in 2011: Only one had homered and they were batting a cumulative .098 with 33 strikeouts. But Desmond swung at that fateful slider and deposited it into the left-field seats to tie the game.

And, finally, with the bases loaded in the 10th inning and danger imminent, Brad Lidge threw the pitch with which he has forged a 10-year career. It was a slider, but it did not move like a Brad Lidge slider should. It plunked Jonny Gomes in the left elbow, and the game was over.

For the first time since Aug. 8, 1998, when Mark Leiter drilled Richard Hidalgo, a Phillies game ended on a hit by pitch.

"Normally that's a pitch for me, that when I release it, I know what it's going to do," Lidge said. "That one didn't go where I thought it was going to go."

It was hardly a bloody Sunday because the Phillies remain 37 games over .500 and the best team in baseball. But the margin between them and their best National League competitors - Milwaukee and Atlanta - is slimmer.

The Phillies lost a series on the road for the first time in two months, the last being June 17-19 at Seattle.

Through 26 outs, it certainly did not look like a loss. The story was Michael Schwimer, pressed into his major-league debut in a tight game, keeping it winnable after a horrific beginning to his career.

"I was thinking that it can't get any better than this," Schwimer said. "And after a few pitches, I was thinking that it can't get much worse than this."

The first warm-up pitch Schwimer threw sailed to the backstop. The second pitch he threw to an actual batter was a 92-m.p.h. fastball mashed by Danny Espinosa for a game-tying home run in the sixth.

Schwimer, however, lasted three innings and only that one mistake burned him. He struck out the side in the seventh with at least 60 family and friends watching him pitch minutes away from his Alexandria, Va., home.

Then Bastardo took the ball and easily fanned the first two hitters he faced. He jumped ahead 0-2 on Desmond, and two pitches later Carlos Ruiz called slider for the win, one that never happened.

"I made a couple of tough pitches to him, and he made adjustments," Bastardo said. "He made me pay for that. That happens."

Contact staff writer Matt Gelb at mgelb@phillynews.com or @magelb on Twitter.