The Nationals swept the three-game series to improve their record to 49-85.
It looked like Washington left-hander John Lannan was going to have his third straight bad outing, but he ended up having a quality start.
In the first inning, Lannan got off to a slow start as he gave up a two-run homer to Manny Ramirez. After walking Jeff Kent and hitting James Loney with a pitch, Lannan retired eight straight batters and didn't give up another run in the next 5 2/3 innings.
"I thought the pitch to Manny was a good one. I just tip my cap to him. I just moved on," Lannan said. "I attacked the strike zone a little more. I wasn't nibbling at the corners. I was down in the zone. I was confident in my stuff. I trusted my fastball a little more today. That's what I've been doing all year and I need to get back to that."
The Nationals gave Lannan (8-12) more than enough run support. In the bottom of the first, they scored five runs off left-hander Clayton Kershaw. With one out, Cristian Guzman hit a 2-1 pitch over the left-field wall to cut the Dodgers' lead in half. He was credited with a single in the next inning after being thrown out trying to stretch a hit into a double.
After the Guzman homer, Ryan Zimmerman doubled and Lastings Milledge walked. Ronnie Belliard followed with single to left to drive in Zimmerman and tie the score at 2. Elijah Dukes followed with a three-run homer.
Willie Harris had a two-run single in the fifth inning, and Guzman had an RBI double in the sixth. Those three runs were scored off reliever Ramon Troncoso.
In the seventh inning, Dukes hit his second homer of the game, a monster shot over the left-field wall off Cory Wade. It was Dukes' first multi-homer game of his career.
"I felt off balance a little bit [during the at-bat]," Dukes said. "I told myself to stop rushing because I have a tendency to do that. He threw the fastball again and my hands took over."
In limited action this season, Dukes is hitting .270 with eight home runs and 27 RBIs. Manager Manny Acta wondered aloud what might have happened if Dukes didn't miss 72 games this season because of injuries. He returned to the lineup on Wednesday after missing time because of a right calf injury.
"He brings to our lineup what we desperately need, and that's why it's so good to have him in there," Acta said. "He gives us the threat every time he steps to the plate. He has a chance to hit the ball over the fence. That's how strong he is. That's something we have lacked in our lineup, mainly because of the injuries to him and Wily Mo Pena."
With a little more than a month to go, Dukes said he would like to hit 20 home runs for the season.
"I just want to stay healthy now. ... Getting hurt is depressing," Dukes said.
Guzman added a triple in the eighth inning, driving in Aaron Boone and accomplishing the rare feat of hitting for the cycle. Guzman is just the second player in Nationals history to do so. Outfielder Brad Wilkerson did it against the Philllies on April 6, 2005.
"I feel great. As you can see, I'm still sweating," the switch-hitting Guzman said. "It's hard to do. When other players do it, you feel great and happy."
Acta acknowledged that he was concerned about Boone scoring all the way from first because the veteran is coming off a calf injury. But Boone said he didn't have any problems running the bases.
"It was nice [for Guzman]. I was fine," Boone said. "The ball was in the gap. Let's get to steppin'!"
The team could be seen jumping for joy in the dugout after Guzman reached third.
"We were all going crazy because it's a good thing for him," pitcher Jason Bergman said. "And if it's good for him, to see a smile on his face, it's good for our team. And we'd like to be a little happier around here.
"It was a great feeling in a season of not-so-happy memories. We have been playing well of late. It's just good to see a smile on everybody's face."
Bill Ladson is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.