Milwaukee’s Ryan Braun flips his bat after striking out against Edwin Jackson in the first inning. Braun finished 0 for 4 while Jackson delivered seven shutout innings. (Jeffrey Phelps/Associated Press)

After the Washington Nationals shredded another victim Thursday night, a speed bump shaped like the Milwaukee Brewers, they reached a place that for years they could only imagine. When they look up, all they see is possibility. There are no teams to block their view. Late summer is approaching, joy is replacing disbelief and no team in baseball has a better record.

The Nationals thumped the Brewers, 8-2, at Miller Park for their sixth consecutive win. Adam LaRoche homered for the third straight game, Steve Lombardozzi smoked a game-breaking, three-run triple in the second inning and Edwin Jackson pitched seven scoreless innings. They played clean defense, snatched extra bases, took an eight-run lead and exchanged purposefully goofy low-10 handshakes.

The methodically dominant performance pushed the Nationals into uncharted territory. They stretched their lead in the National League East to a season-high five games over the idle Atlanta Braves. At 59-39, they moved to 20 games over .500 for the first time since baseball returned to Washington. (A Washington club last stood so far over .500 when the 1945 Senators finished 87-67.) They share the best record in the major leagues with the New York Yankees. Since the Nationals came into existence, they have never been better.

“If we play up to our abilities, we’ll be fine,” Manager Davey Johnson said. “We can win a pennant.”

The Nationals’ front office convened here to prepare for the July 31 trade deadline. It was suggested to an American League scout that the Nationals might not tweak their roster much between now and then. “Well, yeah,” he replied. “Why would they?”

Why, indeed? Their pitching staff has the best collective ERA in the majors at 3.21. In July, they have scored 117 runs, more than any other team. They have played the past five games without Ian Desmond, and they will get Jayson Werth back soon, perhaps inside of a week.

“Guys have been pouring out their guts to play hard,” Jackson said. “We’ve had times where we’ve been swept. Once you get in a rhythm and get the ball rolling, we all know in the clubhouse what we’re capable of doing. It’s just a matter of doing it. We’re doing that right now.”

Last weekend, the Nationals suffered a heart-wrenching, nine-run blown lead against the Braves and lost again the next afternoon. Their lead in the NL East had been whittled to 11 / 2 games. They responded by winning that night, and then the five games that followed.

“It could have been a turning point in the season,” third baseman Ryan Zimmerman said. “To reel off some wins to get that gap between us again, it shows you what kind of team this is.”

Now their road appears to only grow easier. Of their final 64 games, 41 will come against teams that currently have a losing record.

Thursday night, the Nationals encountered a Brewers team that had lost six straight games and gave them no chance. They scored four in the second inning, a barrage that started when LaRoche ambushed starter Yovani Gallardo. He crushed the first pitch of the inning into the visitors’ bullpen, his 19th home run this year.

“He’s got some pretty good off-speed stuff,” LaRoche said. “I was going to hunt a fastball early.”

Gallardo settled, but Roger Bernadina kept the inning alive with a two-out walk. Jesus Flores rolled a groundball through the right side, a sure out had Bernadina not been running with the pitch and vacated the swath of dirt between first and second. Gallardo fell behind Jackson with three straight balls, and he eventually walked the pitcher with two outs on a 3-2 fastball.

The baseball gods would not tolerate such a cardinal sin, and Lombardozzi would not allow Gallardo a reprieve. Lombardozzi ripped a 1-2 curveball down the first base line and into the right field corner. All three runners raced home, and Lombardozzi cruised into third with his first career triple. The Nationals had made five outs and led, 4-0.

“When you have an offensive explosion like we had, it definitely motivates you to pump the strike zone and let the defense play behind you,” Jackson said.

The Nationals added three more runs in the fifth, constantly challenging the Brewers’ outfield arms. Jackson started the inning with a single to right. With one out, he raced from first to third on Bryce Harper’s hard single to right, a feat few pitchers could match. He scored when Zimmerman singled, Harper going from first to third. LaRoche added another RBI with a groundout, and Michael Morse finished the rally by scoring Zimmerman from second.

Jackson saved his best pitches for the most crucial moments. He pitched around eight hits. The Brewers stranded multiple runners on base in four of the first five innings, and they left nine runners on base with Jackson on the mound. Between his last start, in which he allowed one run in seven innings, and Thursday night, Jackson lowered his ERA to 3.52.

He escaped his biggest jam in the sixth. With a man on and two outs, Danny Espinosa made a diving play on Jonathan Lucroy’s grounder up the middle to hold Rickie Weeks at third base. Cesar Izturis then chopped the ball into the hole between first and second, and Lombardozzi made a lunging stop and an accurate, spinning throw to leave the bases loaded. Jackson pumped his fist and walked off the field.

Jackson pitched one more inning. He finished his performance with a popup from Ryan Braun, the reigning MVP, in foul territory to strand a runner on second. Jackson walked off the mound and accepted handshakes and high fives. The Nationals were on their way to another win, and things for them had never been so good.

“Those guys deserve it,” Johnson said. “They’ve hung in there when times were really tough. We got a little healthy. Shoot, they’ve earned it.”

In the clubhouse, the Nationals’ milestones were met with a mixture of pride and weariness. Asked what it meant to own the best record since baseball returned, Zimmerman, who was around for almost all of the losses, replied, “Nothing.” He will wait until September before he celebrates.

“If you would have asked us in spring training, we would have said, ‘Yeah, we’ll take it,’ ” LaRoche said. “Now that we’re there, we want some more. It’s time to get greedy and pile it on.”