With some help from the Astros and the Pirates, the Reds have climbed from sixth place to fourth in a matter of three days, though their lead is slim.
The sweep gives Cincinnati its fourth consecutive victory and seventh win in its past nine games. The Reds went 5-2 on the homestand after going 5-4 on last week's road trip, which was just the second time since 2006 Cincinnati had managed a winning record on a road trip.
Granted, four of their five wins this homestand came against the Nationals, owners of the worst record in baseball, but for a Reds team that entered the series just 12-23 against sub-.500 opponents, it's a step in the right direction.
Cincinnati led, 6-3, entering the ninth, but Washington pulled to within one when Joey Votto let a grounder roll under his glove at first and closer Francisco Cordero gave up two runs in his fourth appearance in as many nights. Cordero had to work out of a jam with the go-ahead run at first to secure his 18th save of the season.
"It's an ugly win, if there is such a thing," Reds manager Dusty Baker said. "I don't think there's such a thing as a pretty loss, but if there's an ugly win, that was one of them. We'll take it, but it wasn't a pretty one. We made a lot of mistakes, but we won that one. I enjoy all victories, but it's hard to enjoy that one as much when you don't play as well as you'd like the team to play."
And on the same day he was selected to his first All-Star Game, Volquez didn't pitch as well as he wanted to, either.
After retiring six of the first seven batters he faced, Volquez ran into trouble in the third, when he gave up a single, hit Nationals starter Collin Balester with a pitch and loaded the bases with a walk of Felipe Lopez. Volquez surrendered an RBI single and a walk before walking in a run. Paul Lo Duca hit into a double play to end the inning.
"I just had to control myself and my emotions," Volquez said. "I told the umpire I was mad at him because he didn't call strikes, but [pitching coach] Dick [Pole] told me, 'Don't show them you're mad. Just control the ball.'"
Volquez (11-3) regained control and allowed just two hits from then on, finishing with six innings pitched and three runs on five hits with three walks and three strikeouts.
Ken Griffey Jr. walked and Brandon Phillips singled with two outs in the fourth before Adam Dunn sent Balester's 2-2 fastball 381 feet into the Nationals' bullpen in right field, tying the game, 3-3.
Cincinnati took a 5-3 lead in the fifth when Davis Ross' double plated Votto and Hairston's fielder's choice scored Ross two batters later. Hairston's big single in the eighth, his eighth hit and third RBI of the series, gave the Reds enough room for the victory.
"That run [Hairston] got was huge," Baker said. "We wouldn't be where we are [without him]. He has been awesome. He's been one of the best finds any team could have."