"If that's not No. 1 today, wow!" Wainwright said. "Who knows where that inning goes if he doesn't make that play? Sometimes you've got to sit back and applaud."
The Nationals bunched three hits and a walk in the fourth, but were held to one run thanks to Kennedy's lunging stop on Austin Kearns' smash up the middle -- followed by a flip from his back to shortstop Cesar Izturis for a forceout. Kennedy was on the grass behind second after sprawling to make the stop, then rolled over and got the ball to Izturis just in time.
"I asked him, 'Is that the best one you've made?"' manager Tony La Russa said. "It's hard to believe he can make a better one than that. Anybody."
That was the only Nationals out in a string of five at-bats, preceded by two hits and followed by a single and a walk. They had the bases loaded before Wainwright recovered from a 3-1 count to get Jesus Flores on a bases-loaded groundout for the third out in an inning that could have gone sour.
"I don't know about great, but it was a good play at that point of the game," Kennedy said. "It's good to be able to help out."
Yadier Molina had two hits and two RBI and Wainwright also drove in a run from the eighth spot in the lineup, where manager La Russa is again placing his pitcher. The Cardinals' 4-1 start is their best since 2000, when they were 7-1, but this is a season that began with reduced expectations.
"This team is not going to embarrass us," La Russa said.
Nick Johnson was 3-for-4 with his first home run and two RBI for Washington, and Flores' two-run shot off Anthony Reyes cut the deficit to a run in the ninth. Randy Flores came in and made one pitch, getting Cristian Guzman to fly out, for his first save of the season and fourth of his career.
The Nationals have lost three in a row after winning their first three games of the year. Manager Manny Acta said failure to control the Cardinals' 6-7-8-9 hitters, who were a combined 5-for-12 with four RBI and four walks, was the key.
"We know when we're going against guys like Wainwright we have to try and play a perfect game, and today we just couldn't throw strikes to the bottom of the order," Acta said.
Matt Chico (0-1) allowed four runs on eight hits in six innings, all but one of them coming in a two-run second and two-run third, with a bases-loaded passed ball by Jesus Flores resulting in an insurance run in the eighth. That run scored after Jesus Colome walked Kennedy and pinch hitter Chris Duncan, the Nos. 7 and 8 hitters, and Ray King walked No. 9 hitter Izturis -- all with two outs.
Colome has walked seven batters in four innings over three appearances, including three in 1 2/3 innings on Saturday.
"He's never been known to have Greg Maddux control, but he can throw the ball close to 100 mph," Acta said. "That's why he's in the game, and he's very valuable to us. He just got a little wild there."
Cardinals starters have allowed four runs in 30 2/3 innings, an 0.88 ERA. And four St. Louis pitchers -- Chris Carpenter, Mark Mulder, Joel Pineiro and Matt Clement -- started the year on the 15-day disabled list.
Wainwright (1-0), whose opening day start was wiped out by rain while leading the Rockies 5-1 in the bottom of the third on Monday, allowed two runs on eight hits with four strikeouts and one walk.
- Duncan had missed three games with a strained left hamstring, and La Russa said he likely could return to LF on Monday.
- Mulder threw 2 1/3 innings in an extended spring training game Saturday, allowing two runs on five hits with four strikeouts and no walks while throwing 47 pitches. The timetable remains early May for the left-hander.
- Pineiro, who had to basically start from scratch in spring training after shoulder tightness stopped him for two weeks, is set to throw a rehab start for Double-A Springfield on Tuesday and hopes to join the rotation after that.
- Guzman was 0-for-5 after hitting safely in the first five games.
- La Russa gave closer Jason Isringhausen, who worked three of the first four games, a day off.