WASHINGTON -- The Baltimore Oriole bullpen need some rest. Jason Hammel gave them most of Memorial Day off.
Hammel turned in his longest start of the season and Nick Markakis and Yamaico Navarro each drove in two runs as the Baltimore Orioles defeated the Washington Nationals 6-2 Monday before a sellout crowd of 41,260 at Nationals Park.
After a series of short efforts by starters, an injury to reliever Tommy Hunter and a 37-pitch outing by closer Jim Johnson Sunday, Hammel turned in a quality start that was timely.
"He was good. He was the difference today," Orioles manager Buck Showalter said. "We'd have all signed up in blood for that today."
Manny Machado added a double and two singles, Chris Davis had two hits and scored twice, and Adam Jones had a double and an RBI single as the Orioles (28-23) piled up 15 hits in winning for the fifth time in seven games.
Hammel (7-2) pitched eight innings, allowing eight hits and two earned runs with eight strikeouts and no walks.
"The fastball command, which I've been searching for, was getting closer and closer and closer, and today was finally there," Hammel said. "And a small adjustment I made with my slider added a little more depth and a lot more swings and misses, and I just stayed aggressive."
Added Showalter: "You give (catcher Matt) Wieters that type of repertoire to work with, he's going to make it tough."
Hammel improved to 6-0 with a 3.16 ERA in eight career starts against Washington, including 4-0, 3.25 at Nationals Park.
Ryan Zimmerman had two hits and an RBI for the Nationals (26-25), whose offensive woes continued.
"I think we just haven't been able to consistently up and down the lineup put together good at-bats day in and day out," Zimmerman said. "We just gotta keep working, keep getting better each day. There's a lot of season left but we need to get going."
Washington's Gio Gonzalez (3-3), who fashioned a 1.29 ERA in his three previous starts, struggled with his control, and it eventually caught up with him.
Davis walked to open the Oriole fourth and Wieters singled. Steve Pearce flied to deep left, and Davis tagged, just beating Tyler Moore's throw at third. On a 3-2 pitch, Navarro singled home Davis to tie the score 1-1.
After Hammel bunted the runners to second and third, Markakis hit the first pitch from Gonzalez for a two-run single, extending his hitting streak to 12 games.
In the fifth, Jones led off with double, went to third on a broken-bat single by Davis, and scored on a sacrifice fly by Wieters to make it 4-1.
Gonzalez, in his shortest outing since April 30, left with two outs in the sixth. He surrendered four earned runs on eight hits, while striking out three and walking four.
Washington, playing without Bryce Harper, got a run back in the sixth when Denard Span tripled and scored on Zimmerman's single.
The Nationals (26-25) had several additional chances to plate runs Sunday, but went just 2-for-11 with runners in scoring position.
"Today wasn't our day," Nationals catcher Kurt Suzuki said. "We were getting some pitches to hit, and fouling them off or mis-hitting them or popping them up or whatever."
Navarro, whose RBI in the fourth was his first in seven games as an Oriole, made it 5-2 in the seventh when he singled home Davis.
Jones closed out the scoring with an RBI single in the eighth.
The Nationals broke on top when Adam LaRoche led off the second inning with a single, stole second and scored on Moore's double.
NOTES: An MRI revealed no structural damage to Harper's ailing left knee, but he was diagnosed with bursitis in the knee. Manager Davey Johnson said he could return as the DH Wednesday or Thursday at Camden Yards. Harper injured the knee May 13 when he ran into the wall in Los Angeles, and aggravated it Sunday when he slid head first twice and fouled a ball of it. Roger Bernadina started in RF. ... The Nationals placed Ross Detwiler (right back muscle strain) on the 15-Day DL retroactive to May 16 and recalled LH reliever Xavier Cedeno from Triple-A Syracuse. ... Machado leads the majors with 23 doubles. ... RHP Kevin Gausman (0-1, 7.20) starts for Baltimore Tuesday. The Nationals will call up RHP Nathan Karns from Double-A Harrisburg to make the start.