In the ninth inning, manager Davey Johnson decided to use closer Henry Rodriguez for the third straight game. And for the second time in three games, Rodriguez wasn't effective. When he left the game, the Padres had the bases loaded with one out and the go-ahead run at the plate.
In came left-hander Sean Burnett, who has been seldom used this season. It took six pitches for Burnett to induce Jesus Guzman to hit into a 1-2-3 double play to end the game.
"Obviously, [Johnson] has the confidence to bring me in in that situation," Burnett said. "I was trying to go in there and throw strikes and make something happen. Fortunately, tonight, it worked out in my favor."
After the game, Johnson said he still had confidence in Rodriguez as his closer.
"I was probably asking him a lot. That was his third day in a row. He threw a lot of pitches [against the Reds]," Johnson said. "I will probably give him [the day] off tomorrow -- regardless. But I still have a lot of confidence in him. After the game, I told Henry, 'You are my man, I still have a lot of confidence in you.' That was the first time he has actually been wild."
Left-hander Ross Detwiler started for Washington and had his toughest start of the season. He pitched five innings and allowed five runs -- four earned -- on seven hits.
"The team could tell I didn't have my best stuff tonight, but they kept me in the game," Detwiler said.
Detwiler was given a 1-0 lead in the first inning, when Desmond scored on a groundout by Adam LaRoche. The game would go back and forth after that.
The Padres would tie the score when Yonder Alonso scored on an error by Harper in right field.
But Harper would make up for the error in the third inning. The Nationals would score three runs off right-hander Tim Stauffer, with Harper capping the scoring by hitting his homer over the center-field wall.
"I was trying to go up there and get a knock. That's all I was worried about. I was trying to get something I could drive and go out of the ballpark," Harper said. "I have guys around me that are hitting very well. It get a little easier when guys are hitting the ball."
Padres manager Bud Black came away impressed by what he saw from Harper.
"He's a talented, young player, an exciting, young player," Black said. "He plays hard, runs the bases hard, and looks like a guy who takes an aggressive swing. At 19, that says something."
After touching home plate, Harper, playing his 15th game, was given a curtain call and acknowledged the fans by stepping out of the dugout.
"I was pretty excited about that. I wasn't sure if I should have went up there, but all the veteran guys said to go get it, so I did. It was cool," Harper said.
But the Padres would tie the score off Detwiler in the fourth. They had runners on second and third with one out, when Orlando Hudson singled to center field. Alonso scored easily, but Chase Headley barreled into Sandy Leon and scored the third run of the game for San Diego.
Leon, 23, was clearly in pain and had to be helped off the field by assistant athletic trainer Mike McGowan. He was diagnosed with a high right ankle sprain and will go on the disabled list.
It marks the second injury by a Nationals catcher in the last three days. On Saturday, Wilson Ramos tore his ACL while going after a passed ball against the Reds. He is expected to be out for the season.
"It was a clean play. He was waiting on the throw and the runner beat the throw," Johnson said. "[Leon] is such an outstanding young man. It was his first big league game, and [he was] all pumped up. He is hurt in his first game, that's tough."
Hudson would later score on a sac bunt by Stauffer.
The Padres took the lead in the fifth inning on an RBI single by Headley.
But it was the Nationals who prevailed and won their 22nd game of the season.
"Overall, it was a good game, except for an injury," Johnson said.