BALTIMORE -- Mark Trumbo's walk-off single in the 12th inning off Jacob Turner gave the Orioles a 5-4 victory over the Nationals on Tuesday night at Oriole Park at Camden Yards.

Baltimore is riding a six-game winning streak and now has the best record in the Majors after securing back-to-back victories in the opening portion of the Beltways Series. The O's, winners in five consecutive season series against the Nationals, are now guaranteed at least a split as it shifts to D.C.

"This is a big game [with] a great pitcher on the mound for them [in starter Max Scherzer]," Trumbo said. "We knew we're really going to have to fight, and this is definitely a good win."

Adam Jones started things off with a one-out single before hustling over to third on Manny Machado's single into center field. After Turner intentionally walked Chris Davis, Trumbo lined the first pitch he saw into left field to end the game.

With a pitching duel for most of the game, Adam Lind opened up a lead for the Nats with a three-run, pinch-hit homer off of Orioles starter Ubaldo Jimenez in the eighth inning. Jimenez, who exited to solid applause, kept up with reigning National League Cy Young Award winner Scherzer for most of the night. Jimenez went 7 2/3 innings, giving up four runs -- including Daniel Murphy's solo shot -- and cruised until his final frame.

• Ubaldo commands fastball, looks to get on roll

"I was able to, in the first inning, command the fastball right away," Jimenez said. "I felt good, I thought everything is good. I just had to have confidence and execute the pitches."

Scherzer, who held the Orioles hitless until Seth Smith's one-out, sixth-inning homer, limited Baltimore's big bats for eight frames. The only other O's score on Scherzer came on Adam Jones' line-drive, first-pitch homer in the eighth. The righty struck out 11 for the second consecutive outing.

But the Nats' bullpen was unable to make Scherzer's stellar outing hold. Left-hander Enny Romero could not hold a two-run lead in the ninth inning as the Orioles sent the game into extras.

"Takes a big emotional toll," Nats manager Dusty Baker said. "One of the biggest downers in baseball is when you blow a game late, especially when you have a lead like that a couple times this week. It certainly tested my team's emotional strength and stability, and we'll see how we come out of this."

MOMENTS THAT MATTERED

Harper's shows off his arm: Baltimore had a chance to win the game in the 11th when J.J. Hardy tried to score from second on a single by Caleb Joseph. But Bryce Harper fired a game-saving throw 99.7 mph, his hardest throw as tracked during the Statcast™ Era, to the plate to nail Hardy at home and extend the game.

"That's what stars do," Baker said. "He had a good jump. He got a good ball to throw with, and he threw it on the money. He executed perfectly. That's how you draw it up." More >

Verrett pitches in: With a depleted bullpen, Logan Verrett, who won his season debut last month in extra innings in New York, tossed three scoreless innings to pick up his second victory.

"That's just how I drew it up. My first two outings with the Orioles, that's how I dreamt it would go," Verrett joked of the extra-innings madness his first two games. "I was just trying to keep us in that ballgame. As long as we're the home team in extra innings, we're always going to have a chance to win it. I was just trying to keep it close, make pitches. Fortunately, I was able to get some early contact and keep my pitch count pretty low. ... You kind of feel like with this team, it's just a matter of time until we score. There's never really a doubt in that dugout."

QUOTABLE

"Really? Lot of baseball to be played. So far, so good. We've played a tough part of the schedule, not that any part is easy up here. ... You never know how a season is going to play out. Our guys have grinded through the first month and some odd half, and a lot of it has had to do with the pitching." -- O's manager Buck Showalter, on his club having the best record in the Majors

SOUND SMART WITH YOUR FRIENDS

Lind gave the Nats the big blow they needed to help chase Jimenez from the game. After Anthony Rendon's single and Matt Wieters' blooper, Lind knocked his third pinch-hit home run of his Nationals career, which is tied for the most in club history.

"I just try and be loose and just try and have an at-bat," Lind said. "I try not to put too much pressure on it because you're kind of expected to get out. So I think from the advantage from mental side of it is in my favor."

MURPHY EJECTED

Murphy was ejected before the start of the 10th inning for arguing with home-plate umpire Laz Diaz. Murphy had taken issue with a called third strike against him in the ninth and expressed his displeasure from the dugout before the start of extras when Diaz tossed him.

Murphy, normally not one to be animated on the field, went out to argue with Diaz after the ejection, and Baker had to get between the two.

"I think we had some disagreements on some calls during the game," Murphy said. More >

REPLAY REVIEW

Machado's routine grounder was flubbed by second baseman Wilmer Difo in the 10th inning. Difo, who entered the game for an ejected Murphy, bobbled the ball -- but it was initially ruled that he lost possession on transferring it. The O's challenged the call, and it was overturned after one minute, 28 seconds, with an error charged to Difo. It placed runners at first and second for Baltimore.

WHAT'S NEXT

Nationals: This matchup shifts to Washington for a two-game series at Nationals Park at 7:05 p.m. ET on Wednesday. The Nats will send right-hander Stephen Strasburg to the mound. In two career starts against the O's, he has a 2.25 ERA.

Orioles: Baltimore will send southpaw Wade Miley to the hill in the first of two games in D.C. on Wednesday. Miley was hit by a pair of line drives in his last start that knocked him out of the game in the first inning. But the lefty has done well when he's in, pitching to a 2.27 season ERA.

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