WASHINGTON -- The road that was once filled with jarring potholes has become nice and smooth for the Red Sox, who no longer need to wear their home whites to look like an upper-echelon team.

In reeling off a 6-4 victory over the Nationals on Wednesday night in the nation's capital, the Red Sox won for the eighth time in their past nine road games. After opening the season at a 9-12 clip on the road, Boston has won its past three series away from Fenway.

Then again, it doesn't seem to matter where the Red Sox are playing these days. They just seem to win. Boston is in the midst of a 16-5 run that has vaulted its overall record to 44-27, the second-best in the Majors.

"It's a nice feeling to find ways to win on the road," said Red Sox manager Terry Francona. "It has been tough for us, and I think that when you win a couple, even a veteran team, you start to see a little more confidence. I think a bullpen like ours always gives you a chance on the road. Even on some nights where things don't go perfect, we've found some ways to get out of innings because our bullpen is deep."

In this one, the Red Sox got a little bit of everything, starting with a three-run homer from David Ortiz in the fourth that put the left-handed slugger over the 1,000-RBI plateau in his career.

"That was a great swing," said Red Sox second baseman Dustin Pedroia. "He stayed through that ball and drove it to right-center, the biggest part of the park, too. That's a great sign. He's been swinging the bat well for the last three or four weeks now."

Jon Lester went six innings, allowing six hits and three runs. He walked two and struck out six, earning his sixth victory and eighth quality start.

"For any pitcher, it's a good sign when you're breaking bats and you're missing the middle part of the plate," said Lester. "The majority of hits tonight were broken bats. It's tough sometimes to swallow -- especially when you give up a run or two because of it, but you have to tell yourself that 'Hey, I executed the pitch I wanted to and they just got enough bat or enough strength on it to get it where our guys weren't.' Like I said, it's always good to be breaking bats."

As for the Boston bullpen, it continues to stop bats. With the potential go-ahead run at the plate with two on and two outs in the bottom of the eighth, Hideki Okajima struck out Ronnie Belliard.

"He made some good pitches," said Francona. "He doesn't get rattled. He comes in and executes his pitches. When you have guys who can do that, it makes your team look better, it makes me look smarter."

Okajima's clutch strikeout put the ball in the hands of closer Jonathan Papelbon, who notched a 1-2-3 ninth to earn his 17th save in 18 opportunities.

The Nationals did take the lead early, thanks to a hit that was scary for the Red Sox. With one out and one on, Elijah Dukes hit a grounder to short, only to have his bat split in half. The top half of the bat came flying right by shortstop Nick Green, who barely dodged the splintering wood. The ball went through his legs and into left for a hit. The piece of bat had such a sharp end that it wound up standing straight up in the short grass in left field.

"It happened so fast, you don't really have time to react. I did what I could do to get out of the way of the bat," said Green. "That's all you can do."

Anderson Hernandez followed with a broken-bat single to left-center, making it 1-0 Nats.

"There were some unique hits. The one inning, [Lester] gives up the back-to-back hits, we get a ball to short that Greenie almost gets stabbed or impaled," Francona said. "Then we get a jam shot. There were some hits and there were three runs, but I thought his velocity was good. He got stronger as the game went. I thought he was pretty good."

After being no-hit by Nationals right-hander Craig Stammen over the first three innings, the Boston bats got in full swing. Pedroia led off the fourth with a double to left and Kevin Youkilis drew a walk. With two outs, Ortiz ripped a prodigious three-run blast over the fence in center, No. 296 of his career. Suddenly, the Red Sox had a 3-1 lead.

"I think he made a pitcher pay for a mistake, which is kind of what we're used to seeing," said Red Sox hitting coach Dave Magadan, who was ejected in the fourth inning. "He left a changeup out over the plate and David hammered it. He didn't roll over on it, he didn't pop it into left, he hit it where he's used to hitting it. It continues to be nice to see."

While Lester continued to hold down the Nats, the Red Sox added to the lead. Pedroia ripped an RBI single to right in the fifth. Lester helped set it up with a sacrifice bunt that moved Green to second.

In the sixth, Jason Varitek snapped a 53-at-bat homerless drought by clubbing a two-run shot to right, giving the Red Sox a 6-1 lead.

"Tek's swing -- that was about as far as you can hit a ball," said Francona.

The cushion provided by Varitek lessened the sting when the Nationals chipped away with a two-run single from Josh Willingham in the sixth.

Justin Masterson came on for the Sox in the seventh, but he was shaky. After a double by Josh Bard, Cristian Guzman belted an RBI triple down the line in right, making it a two-run game. The Nationals nearly tied it when Ryan Zimmerman followed with a fly ball to deep left-center. But Jacoby Ellsbury tracked it down just in front of the wall to end the inning. As Ellsbury and the Red Sox ran back to the dugout, Francona exhaled.

"We've got a good thing going right now," said Francona.