WASHINGTON -- Tough to decide who was more pumped up by Bryce Harper's go-ahead, two-run double in the eighth inning: Harper, who clapped and yelled as he stood at second base, or his new manager, Dusty Baker, who punched the frigid air with his gloved hands and screamed some, um, choice words from the dugout.

Indeed, based on what the TV broadcast showed Baker saying Tuesday night, he was expecting to get chastised by his mother.

"I'm not kidding," he said. "She'll call me as soon as I get in the car."

Harper's big two-out hit on the first pitch thrown by reliever Eric O'Flaherty broke a scoreless tie and lifted Washington past Atlanta 2-1 for the Nationals' 12th consecutive home victory against Atlanta.

On a windy night with the temperature dipping into the 50s after the first pitch, the Nationals improved to 5-1, the first time a Washington-based team had that record since 1951.

"I was just excited we didn't have to play extra innings," Harper said with a hint of a grin when asked about his animated reaction. "I saw the whole dugout was pretty fired up about it."

The Braves fell to 0-7 overall, their worst start since opening the 1988 season with 10 losses.

"It's been a tough stretch," said Atlanta catcher Tyler Flowers, who was 0-for-4 with three strikeouts. "I feel like we're playing good ball, and we just can't get that big hit or get that big out or we come up with a little miscue or something that snowballs an inning on us. We're getting close. We're all still very positive in here."

The Braves' futility in Washington is their worst stretch on the road against one opponent since a 13-game skid at the Dodgers in 1951-52, according to STATS LLC.

The winning rally came after Stephen Drew got his first hit as a member of the Nationals and Anthony Rendon walked, both against righty Jim Johnson (0-2). O'Flaherty, a lefty, entered to face the lefty-hitting Harper, who immediately hooked a hit toward the left-field line. Outfielder Jeff Francoeur dove in a bid to make a catch, but the ball went off his glove.

"I saw the left side of the field was open," said Harper, who was 0-for-3 to that point. "Just trying to get something out over the plate I could hit that hole with. Back-spun it a little bit, cut it a little bit."

Said Nationals starter Gio Gonzalez: "The right guy at the right time."

It made a winner of Blake Treinen (2-0), who got Francoeur to ground into a bases-loaded, 6-4-3 double play to end the eighth.

"That's why you like that sinkerballer on your staff," Baker said.

Treinen stayed in for the ninth but was removed after walking Gordon Beckham with two outs. Felipe Rivero then gave up Kelly Johnson's RBI double to make it a one-run game before earning his first save of the season by striking out Mallex Smith.

FOR STARTERS

Both starting pitchers were making their season debut, with Atlanta's Jhoulys Chacin brought up from Triple-A Gwinnett on Tuesday and Washington's Gonzalez seeing action for the first time since a March 27 spring-training exhibition. Each threw six shutout innings. Baker said about Gonzalez: "He was very sharp. You wouldn't know that he had missed two weeks."

OOPS

Baker acknowledged it was his fault for accidentally putting on a hit-and-run when Daniel Murphy got doubled off at first base on Jayson Werth's lineout to right in the seventh inning. "I inadvertently touched the wrong part of my body," Baker said. "That won't happen too often."

FEAR THE BEARD

Nationals GM Mike Rizzo's duties apparently include more than making trades, negotiating contracts and hiring managers. He needs to keep tabs on batters' scoreboard photos, too. After Danny Espinosa's at-bat pic showing him with an overgrown beard was replaced by a clean-shaven version, Rizzo issued a statement via a team spokesperson: "This was my decision. I reserve the right to choose the player photos we use on the scoreboard during the game."

UP NEXT

Washington RHP Stephen Strasburg (1-0, 1.50 ERA) is 3-0 with a 0.53 ERA in his past three starts against Atlanta, including a 3-1 victory in this season's second game. RHP Matt Wisler (0-0, 5.40) starts for the Braves.