It’s only the second week of the season, but the Braves may have a difficult time topping the dramatic comeback win they pulled off Friday night against the Nationals.

After scoring a run in each of the seventh and eighth innings and two in the ninth to erase a four-run deficit, Ramiro Pena hit a tw0-run, two-out homer in the 10th to lift the Braves to a thrilling 6-4 win in a series opener at Nationals Park, extending their winning streak to seven games.

“I think there’s a deep part of everybody that thinks that we are going to come back every time it happens,” said Chris Johnson, who had three hits and started the comeback with a two-out homer in the seventh. “That’s a good feeling. You don’t want to do it every time, but it’s good.”

The Nationals were unbeaten at home before Friday and probably felt their 4-0 lead after six innings was safe.

But the Braves, whose 9-1 record is the best in the majors, fought back to tie, then win, sending an early message to the defending NL East champions: This revamped Atlanta team won’t go gently into any night.

Justin Upton’s bases-loaded, two-out infield single in the ninth inning and a throwing error on the play brought in two runs for a 4-all tie, and Pena’s homer in the 10th off Craig Stammen capped the stunning turn of events.

“It was really good,” said Pena, a bench player who has already come through with several big hits and plays this season. “I was just trying to concentrate and take advantage of the opportunities I have. Just doing my job.”

Already this season the Braves have won two games after overcoming four-run deficts in the late innings, and Julio Teheran was their starter both times. But coming back from four down to beat the formidable Nationals on the road was a greater feat than scoring five runs in the last two innings to beat the Cubs 6-5 on April 6 at Turner Field.

“It’s just awesome,” said Evan Gattis, who drew one of three walks in the eighth. “I don’t think we really thought we were going to lose, ever.”

Teheran hadn’t faced the Nationals before Friday, and Bryce Harper didn’t waste time introducing himself to the Braves rookie. Harper hit a two-run homer in the first inning, his fifth. The Nationals added two runs in the second, and for most of the night it looked as if they would cruise to their seventh consecutive home win.

But Teheran settled down and pitched four near-perfect innings throughout the sixth, and the Braves’ offense came to life when Johnson broke through with his seventh-inning homer off starter Ross Detwiler.

“(Catcher) Gerald (Laird) did a nice job with Teheran,” Braves manager Fredi Gonzalez said. “Gives up four runs in the first two innings, then he changed the gameplan, went someplace else with him. And I think we give up two hits the rest of the way, counting Julio and the bullpen.”

After Johnson’s homer gave them life, the Braves got two quick outs in the eighth before getting back to rally mode. Jason Heyward walked with two out against Tyler Clippard. Justin Upton singled. And Gattis walked to load the bases.

B.J. Upton lugged an .094 batting average to the plate and fell behind in the count 1-2 with the bases loaded. Then the unexpected: He took three straight balls from Clippard for a walk that cut the lead to 4-2. Clippard was booed off the field.

Dan Uggla flied out to the center-field warning track against reliever Drew Storen to end the inning, and the Nationals crowd let out a collective sigh of relief. But the Braves weren’t done. Not even close.

Johnson led off the ninth with a single, and Pena followed with a perfect pinch-hit bunt single. After a Blake DeWitt sacrifice bunt the Braves had two in scoring position. Andrelton Simmons struck out looking, but Heyward walked for the second time in two innings to load the bases against Storen and bring up NL home-run leader Justin Upton.

Upton hit a sharp single behind third base that Ryan Zimmerman fielded cleanly, but his ill-advised throw to second base was late and wide as Heyward came barreling in. Two runs scored on the play to tie the score at 4-all.

“We got some guys on base, and when you get guys on base good things happen,” Johnson said. “Justin had a pretty good at-bat and J-Hey was hustling down the second base, too.”

Johnson’s homer in the seventh was just the Braves’ fourth (and final) hit in seven innings against Detwiler. It set the tone for the late innings, for all the two-out drama that was to come.

“Their (starting) pitcher was throwing really good and we couldn’t do anything against him,” Pena said. “But then we got their relievers in. After we scored the first run, everything started to come together.”

Teheran was charged with four earned runs, six hits and three walks in six innings, all the hits in the first two innings. The only Nationals to reach base against him after the second did so on a pair of walks, including an 11-pitch plate appearance by Harper that was extended when first-time first baseman Gattis missed a pop foul.

“The first thing I did (after the game) was come in here and talk to (Teheran) about his night,” Laird said. “I mean, that’s a big game for him to pitch. It could have got ugly real quick. He gave up two runs (each) of the first two innings, and young guys tend to … that can be a lopsided game there and kill our bullpen. But the kid stepped up.

“I went out there one time and said, ‘You’ve got to battle. No one ever said it’s easy, man.’ And he just said, ‘All right.’ And you could see the change in him. He started feeling more comfortable, he got some outs. He was mixing it up and he did a really good job. I’m happy for him.”

Washington’s first inning began with a leadoff single by Denard Span, initially ruled a throwing error on third baseman Johnson. His throw to first was a little wide to Gattis, the rookie catcher who got a start at first base despite not playing the position in nearly two years since Class-A ball.

Gonzalez did it to keep Gattis’ hot bat in the lineup, since he didn’t want to use an all-rookie battery of Teheran and Gattis. Laird has handled both of Teheran’s starts. The 22-year-old right-hander gave up five runs and eight hits in five innings of his season debut against the Cubs, when the Braves rallied for five runs in the last two innings to win.

After the second inning Friday, Teheran pitched closer to the sharp performances he had in spring training.

“The first two innings I was missing a little bit in the strike zone,” he said. “I’m glad I came out in the next four innings and made the adjustment. (Laird) told me just to slow down a little bit, because that’s why I was missing the zone, I was trying to hurry. But he told me to slow everything down and to keep the team in the game. So that’s what I was thinking.”

Veteran Luis Ayala, acquired from Baltimore in a Wednesday trade, made his Braves debut with a perfect seventh inning. Jordan Walden, Eric O’Flaherty (2-0) and Craig Kimbrel (fifth save) each pitched an inning as the ‘pen cranked out four scoreless innings with no walks and only two hits, both against Walden.