PITTSBURGH -- It seems as if Adam Frazier has been all over the field and up and down the lineup with the Pittsburgh Pirates.

The leadoff spot seems to suit him.

That's where he hit, and hit and hit Thursday afternoon, driving in a career-high four runs as the Pirates beat the Washington Nationals 10-4 at PNC Park.

"It's what I've done my whole life," Frazier said of hitting first in the order. "I've geared my (hitting) approach to it, and it's where I'm most comfortable."

Frazier, who played left field but also has played several infield spots with the Pirates, was 3-for-5 with two singles and a double. Josh Bell homered for the fourth time in six games, and John Jaso added a solo homer for Pittsburgh.

The Pirates (18-23) pounded out 13 hits against four Nationals pitchers. They have won two in a row and four of their past five games. They took two of the three in the series with Washington (25-15), the top team in the National League entering the day.

"It was a bad couple days," Nationals manager Dusty Baker said of his club's two losses in a row. "We didn't play very well. We made a lot of mistakes. Seems like we weren't there sometimes. We just have to up the intensity and up our concentration."

Pittsburgh starter Tyler Glasnow (2-3) allowed four runs -- two earned -- on three hits over five innings, with three walks and six strikeouts.

Washington starter Tanner Roark (3-2) gave up seven runs on eight hits, including both homers, over five-plus innings, with four walks and three strikeouts.

Bell hit his team-high ninth homer with two outs in the second. The blast to right drove in Frazier, who led off the inning with a single, for a 2-0 Pirates lead.

Daniel Murphy followed in the second with a one-out solo homer to right to bring Washington within 2-1.

Pittsburgh tacked on two more in the third for a 4-1 lead on Roark's bases-loaded walk to Jaso and a fielders' choice grounder by Jordy Mercer.

"I feel like my issue all year has been walks," Roark said. "The game is testing me right now. I just have to fight back and not give in, continue to work hard and keep doing my thing."

The Nationals tied it in the fourth on Adam Lind's RBI double and, Glasnow's throwing error with two outs that allowed two more runs to score.

Glasnow has struggled in his first season in the rotation, but manager Clint Hurdle was a lot more concerned about the error this day.

"I thought there were some improvements, first-pitch strikes, the pitch sequences were cleaner and sharper," Hurdle said. "The biggest gaffe today was not being able to field his position. He gave up two tack-on runs."

Jaso's two-out homer into the bullpen in center put the Pirates back in the lead, 5-4, in the fifth.

"The thing about this game is you just keep playing because you never know. It could be that at-bat where you break through a slump or whatever you're going through," said Jaso, who raised his average modestly five points to .165.

The Pirates chased Roark in the sixth after Chris Stewart singled and Gift Ngoepe walked. Frazier greeted reliever Blake Treinen with a two-RBI double to center, and Josh Harrison's sacrifice fly to left brought home Frazier for an 8-4 lead.

In the seventh, Pittsburgh's Danny Ortiz hit a one-out single to right for his first major league hit. He and Stewart, who singled, later scored on Frazier's base hit to make it 10-4.

"It feels great to be able to get your first major league hit, and not only that but be able to score, especially because when they called me up that's the biggest thing I wanted,," Ortiz said through an interpreter. "I just wanted to make sure I got that first major league hit,"

NOTES: In South Korea, a court upheld Pittsburgh 3B Jung Ho Kang's suspended sentence for a DUI conviction. That casts into doubt when he might be available to the Pirates. ... Pittsburgh gave C Francisco Cervelli a day off from starting. ... Washington gave LF Jayson Werth and 1B Ryan Zimmerman the day off from starting, although Zimmerman entered in the sixth. ... Pittsburgh and Washington don't meet again until the final series of the regular season.