WASHINGTON -- Ryan Zimmerman is getting accustomed to coming to the plate with the game on the line.
"I guess it's pretty easy to get excited and swing at a pitch you don't want to, or maybe swing at a pitch you can't do anything with," said Zimmerman, who is tied with Minnesota's Justin Morneau for the most game-winning hits over that span.
"The biggest thing is to stay relaxed and put the pressure on them."
Pinch-hitter Tony Batista, Washington's last available position player, led off the inning with a single off Ryan Franklin (4-1). Felipe Lopez hit into a force play before Ronnie Belliard singled. Zimmerman then lined a 1-1 pitch to left field, scoring Lopez from second.
"I knew I was up fourth, so if I was up fourth, you know somebody's going to be on base, Zimmerman said. "You think about it the whole inning, and even the inning before."
Chad Cordero (2-2), the fourth Nationals pitcher of the game, threw a scoreless ninth to earn the win. It is Washington's first four-game winning streak since May 22-25.
"He has done some dramatic stuff since he's been up here," Nationals manager Manny Acta said of his slugging third baseman. "He doesn't get rattled."
Franklin was philosophical about his first loss since last Aug. 29.
"I made my pitch and he hit it in the hole," Franklin said. "Not much I can do about that."
The Nationals took a 2-1 lead in the seventh, when Brian Schneider singled off Kip Wells. Ryan Langerhans came on to pinch run, and Nook Logan followed with a bunt single and D'Angelo Jimenez walked to load the bases. Wells gave way to Russ Springer, who retired Lopez before Belliard lofted a sacrifice fly to right.
St. Louis tied the game in the eighth on consecutive singles by Juan Encarnacion, Adam Kennedy and Yadier Molina off Jon Rauch.
Wells, who exited after throwing 116 pitches, has won just once in his last nine starts. But he pitched well enough to win this one, allowing two runs and six hits in six-plus innings.
He singled in his first two at-bats, raising his average to .308. In his first trip to the plate, with two on and two outs in the second, he stretched out an eight-pitch at-bat before lining Tim Redding's 3-2 pitch to right, driving in the game's first run.
The Cardinals left 12 runners on base, frustrating manager Tony La Russa.
"You've got to have productive at-bats. We had some chances," La Russa said. "We have a good offense and we should be doing more."
Wells got out of a bases-loaded situation in the first by striking out Ryan Church on a 79 mph curveball, and wound up taking a shutout into the fifth.
That's when Washington tied the game. Redding reached on a fielder's choice, took second on a wild pitch and scored on Lopez's double into the left-field corner on a full count.
In the sixth, Wells walked Austin Kearns to put runners on the corners with one out. After a visit from pitching coach Dave Duncan, he got Church to ground into an inning-ending 4-6-3 double play.
Tiring on a muggy, 79-degree evening, Redding bounced his 102nd pitch in front of the plate in the seventh. He did get Wells to ground out, but then walked David Eckstein on four pitches and was removed.
Redding went 6 1/3 innings, allowing one run and seven hits. He walked two and tied a career high with eight strikeouts, including Albert Pujols twice.
A 10-year-old boy sitting in the fourth row behind the visiting dugout was hit in the head by a bat when it sailed out of Church's hands on a swing in the fourth inning. The boy was bleeding and carried out of the stands, but the Nationals said later he was OK. ... Logan's diving catch of a sinking liner robbed Eckstein of a hit leading off the game. ... Langerhans' eighth-inning single broke an 0-for-18 slump.