PHOENIX -- Willie Harris picked a good time to snap out of a slump.
Harris had one hit in his previous 18 at-bats before he connected on an 0-1 fastball from Micah Owings (6-3) with one out in the seventh to put the Nationals in front 6-3. The drive to right field was Harris' second homer.
"I'm by far not a home run hitter," Harris said. "I hit two every year, so that's my mark. I'm done."
Asked if he knew how many career homers he has, Harris smiled and replied, "Eight."
When told it was actually nine, Harris raised his arms above his head in mock exultation.
Nationals manager Manny Acta said Harris hadn't gotten down during his slump.
"Actually, he's a very positive, energetic guy," Acta said. "He doesn't put his head down. That's why I'm happy that things worked out for him today."
The Diamondbacks had hoped to regain their swagger in a six-game homestand against San Francisco and Washington. But they've dropped the first four games and will ask ace Brandon Webb to stop the slide on Saturday night.
"It just feels like we're putting some pressure on ourselves at the plate, especially if we're behind a little bit," manager Bob Melvin said.
Arizona has lost nine of its last 11 games overall and its NL West has dwindled to 2½ games over the Los Angeles Dodgers.
The Nationals took a 2-0 lead in the second on a two-run single by Jesus Flores, who left after seven innings after twice being hit in the head with foul tips. The team said the catcher was experiencing headaches and nausea.
Redding entered 0-5 lifetime with a 6.30 ERA against Arizona. But he dominated the Diamondbacks early, allowing only a walk to Owings in the first three innings.
Arizona finally got to Redding in the fourth, when Hudson hit a 1-0 pitch out to right to cut Washington's lead to 2-1.
The Diamondbacks tied it in the fifth. Jeff Salazar drew a leadoff walk, moved up on singles by Owings and Chris Young and scored on Stephen Drew's sacrifice fly.
Owings gave up six runs and eight hits in 6 2/3 innings. He struck out six, hit two and walked none.
"I just kept fighting," Owings said. "I didn't feel like I had my best stuff tonight, and unfortunately you're going to have those nights."
Chris Snyder hit an RBI single in the sixth for Arizona but the game wasn't tied for long. Owings left a fastball over the middle of the plate and Harris lined it over the right-field fence.
"Could be a whole different ballgame," Owings said. "Missed my spot and paid for it. We're in the big leagues. It's going to happen when you don't hit your spot."
Redding went 5 1/3 innings, allowing three runs and four hits. He walked five and struck out one.
- Washington RHP Jason Bergmann starts Saturday night against the Diamondbacks. Bergmann (1-1, 4.50 ERA) has thrown 19 2/3 consecutive scoreless innings.
- Webb has lost two straight starts after winning his first nine.
- With a single in two at-bats, Owings raised his batting average to .297 (11-for-37).