WASHINGTON -- Ryan Howard isn't ready to be compared to Mike Schmidt, no matter what the record book says.
"It means a lot, but in my eyes I've still got a lot of work to do to even get on that type of level," Howard said. "Right now as far as the single-season home run thing, it's an honor and it's a cool thing to be a part of."
Howard hit a three-run shot to center field in the sixth inning off reliever Kevin Gryboski, equaling the club mark set by Schmidt in 1980 -- when the Hall of Fame third baseman led the Phillies to their only World Series championship.
Howard finished 2-for-3 with two walks. His three RBI gave him a major league-best 125 for the year.
"Those numbers are pretty impressive up there," Nationals catcher Brian Schneider said. "When you miss your location a little bit, he doesn't just make you pay with singles or doubles. He makes you pay by hitting the ball a long, long way."
Brett Myers (10-6) allowed three runs in six innings for the Phillies, who began the day a game behind NL wild-card leader Cincinnati. The right-hander yielded eight hits while striking out seven.
"I made quality pitches when I had to and made a couple of mistakes, but we got the win," Myers said.
Alfonso Soriano hit his 42nd home run for Washington, which lost its third straight and eighth in nine games. Armas lasted 3 1/3 innings, allowing five runs and eight hits.
In four of the Nationals' past five games, the starting pitcher has failed to make it out of the fourth inning. Armas allowed eight runs (five earned) in 1 2/3 innings in his previous start, last Wednesday against Florida.
"He's just not giving the performance we are counting on him to give us," manager Frank Robinson said.
Arthur Rhodes struck out Jose Vidro with runners on second and third for his fourth save.
The Phillies scored twice in the first inning, when Rollins and Shane Victorino opened the game with back-to-back singles and scored on Burrell's two-run single. Philadelphia added three more in the fourth on Lieberthal's home run and an RBI double by Rollins, which chased Armas.
Soriano's one-out home run in the third inning landed in the mezzanine section in left-center. The Nationals cut their deficit to 5-3 in the fifth when Ryan Zimmerman hit a two-run triple.
The Phillies scored four in the sixth, including Howard's two-out drive to center. The home run was his 13th in August, breaking Schmidt's previous team record of 12, set in 1975.
"Ryan Howard, I don't have to tell you guys, he's special, man," Phillies manager Charlie Manuel said. "He's tremendous. The only thing he's got to do is do the same thing he's been doing every day for the four years I've seen him, and he'll keep on getting better."
The Phillies added another run in the seventh on a bases-loaded walk by Victorino.
Ryan Church had a run-scoring single for Washington in the eighth. Zimmerman added an RBI double in the ninth before Nick Johnson's RBI single.
Zimmerman finished 4-for-5 with three RBI. His 89 RBI are the most among NL rookies.
- Howard's intentional walk in the first inning was his 19th this season. The Nationals have issued 72 intentional walks, most in the majors.
- Burrell batted sixth for the first time this season.