ST. LOUIS -- Adam Wainwright made the most of his 28th birthday and bobblehead day, becoming the majors' first 16-game winner.

Wainwright dominated most of his six innings in St. Louis' 2-1 victory that gave the Cardinals a three-game sweep of the Washington Nationals.

"Adam by far is the best pitcher I've faced this year," Nationals leadoff hitter Willie Harris said. "That's why he's where he is right now."

Albert Pujols had the go-ahead single on a hit-and-run play in the sixth and Colby Rasmus had two hits and scored twice for the NL Central leaders, who have won five of six and are 29-4 since July 1 in starts by their top three -- Wainwright, Chris Carpenter and Joel Pineiro. Pujols had two hits and was 5 for 10 in the series with an RBI in each game, including a game-winning ninth-inning homer on Friday.

St. Louis was 20-6 in August with a day off Monday, and the .769 winning percentage is the best for that month in franchise history. They're a season-best 22 games above .500 and their 10-game lead over the Cubs is their largest since the end of 2005, when they finished 11 games ahead of Houston.

The Cardinals won on only four hits while leaning on the pitching staff, also limiting the Nationals to four hits. They needed only three hits to beat the Astros 1-0 on Tuesday, getting eight scoreless innings from Wainwright.

"Adam rose to the occasion," manager Tony La Russa said. "Again."

Elijah Dukes had an RBI single for the Nationals, who have lost 10 of 13 and finished 1-6 against St. Louis. Washington was held to seven runs in the series after totaling 24 runs while taking two of three at Chicago the previous series and is 14-14 this month, needing a win on Monday at San Diego for their first winning month since September 2007.

Wainwright (16-7) is 4-0 in his last five starts and has worked at least six innings in 26 consecutive starts, the best streak in the majors. Wainwright is 43-23 since moving to the rotation in 2007 after getting the last out in the 2006 World Series as the closer.

He, Carpenter and Pineiro are a combined 43-19.

"We've got a lot of talented pitchers in this league, and on this team even," Wainwright said.

Wainwright's outing against the Nationals is tied for his shortest in the last 13 starts, and he faltered at the finish with consecutive walks to Adam Dunn and Josh Willingham setting up Dukes' game-tying two-out hit.

"I didn't do anything particularly well," Wainwright said. "I just had a good team behind me. That was what I did on the bump, play for the Cardinals."

The Nationals didn't have a runner in scoring possession until the sixth against Wainwright, who allowed a run on three hits with seven strikeouts and three walks. In his last eight starts, he's 6-1 with a 1.31 ERA and his overall 2.47 ERA is fourth best in the NL.

Ryan Franklin escaped a bases-loaded situation in the eighth and retired the last four outs for his NL-leading 35th save in 37 chances. Franklin has a save in his last 11 appearances.

Left fielder Matt Holliday protected the lead on Willingham's two-out double off the wall with a man on and two outs in the eighth, blocking the carom with his leg and then getting the ball in quickly.

Rasmus singled off Garrett Mock (3-6) and went all the way to third on Pujols' dribbled infield hit before Ankiel's one-out sacrifice fly in the fourth, his first RBI in six games.

Dunn walked three times for the eighth time this season and the 43rd time of three or more. He has an NL-leading 100 walks.

Notes

• Mark DeRosa (sore wrist) was scratched from the Cardinals lineup and replaced by Khalil Greene, who was 0 for 3 and didn't get the ball out of the infield. DeRosa played 3B after a double switch in the seventh.
• Troy Glaus turned an ankle while hitting for Triple-A Memphis Saturday night and is due to visit team physician Dr. George Paletta on Monday. He has been due to join the team along with the September callups.
• Wainwright's six-inning streak is the franchise's longest since Carpenter had a run of 28 in 2005.
• Five of the Cardinals' last six games have been decided by a run, all but one of them St. Louis victories.