PHILADELPHIA -- A.J. Burnett isn't much for numbers except when it comes to strikeouts.
"Good offense up and down the lineup, good starting pitching and good bullpen," Phillies manager Ryne Sandberg said. "Real good combination."
The game was delayed for 24 minutes because of heavy rain, lightning and thunder after the sixth. Burnett didn't return after the weather cleared, having thrown 93 pitches.
Burnett (2-1) gave up one run on three hits and walked two. The right-hander had seven strikeouts to up his career total to 2,215, moving past Jim Palmer into 52nd all-time.
"I do take pride in my strikeouts, so that's pretty cool," he said.
The 37-year-old has relied on precise control, more than power, to accumulate strikeouts in the latter stages of his career.
"I used to do that," Burnett said of being a power pitcher. "I'm old now so I've got to try to pitch. I've had the good hook through my career and being able to change the angle on it has been big. A couple of years ago, I began throwing the two-seamer (fastball) and it's been big for me."
And he has been doing it lately while battling a hernia. He has a 0.98 ERA and 25 strikeouts in 27 2/3 innings since the injury was diagnosed four starts ago.
"It's there," Burnett said of the pain. "It bugged me all day and the next few days it's gone. It comes and goes and it's something I have to deal with."
Said Sandberg, "He's just a battler and gets after it."
Tanner Roark (2-1) had the poorest start of his two-year career, allowing seven runs on seven hits in four-plus innings.
The runs and innings were career-worsts for Roark, who was making his 11th major league start.
"I didn't have command of my fastball, and it's my bread and butter pitch," Roark said. "I also left some balls up. You live and learn."
Howard started the trouble for Roark by hitting an opposite-field, three-run homer in the first. The home run snapped Roark's scoreless streak at 18 innings.
It was the sixth homer of the season for Howard, who is starting to find his swing after combining for just 151 games over the last two seasons due to injuries.
"Right now he's a threat to pop one or make something happen," Sandberg said.
Said Howard, "It's still kind of a game of catch-up for me. Just trying to take it day by day, continue to try to progress and take it as it comes."
Asche connected for a solo shot in the second to make it 4-0. Carlos Ruiz's RBI double in the fourth and Byrd's two-run single in the fifth gave Philadelphia a 7-0 cushion.
LaRoche homered in the sixth. He continued to have success off Burnett, raising his average to .400 (10-for-25) with two homers and six RBIs against the right-hander.
LaRoche, who has been slowed by a quadriceps injury, was lifted after hitting the homer.
Walters, pinch-hitting in the seventh, homered off Mario Hollands with two outs. 7-2. All three of the rookie's hits this season are homers.
But the Nationals, who have come back in nine of their 17 wins, couldn't get any closer.
"We've been coming back a lot, but over the course of a season you can't expect to keep doing it," Washington manager Matt Williams said.
Phillies LHP Cole Hamels (0-2, 6.75) has been scratched from his scheduled start on Sunday because of the flu. Hamels will start Tuesday against Toronto. RHP Roberto Hernandez (1-1, 5.74) now will oppose Nationals LHP Gio Gonzalez (3-1, 3.25) in the conclusion of the three-game series. ... Former Phillies closer Brad Lidge threw out the ceremonial first pitch. Lidge converted all 48 of his save opportunities during Philadelphia's 2008 World Series season. ... Third-base umpire Jim Reynolds left the game after the first inning due to an undisclosed illness and was replaced by Toby Basner. ... Rollins had been hitless in his last 11 at-bats.