Gio Gonzalez delivers another sterling outing Saturday, going seven innings to earn his third win as the Nationals take their second straight in as many days over the Phillies and seventh in a row dating back to last season. (Patrick McDermott/Getty Images)

Saturday afternoon, over nine resounding innings, the Washington Nationals made clear they have finished chasing the Philadelphia Phillies. For years, the Nationals played doormat as the Phillies captured pennants. Their meetings felt “like going to a gunfight with a knife,” General Manager Mike Rizzo said. Not anymore, not after the thorough, 7-1 thumping the Nationals delivered at Nationals Park before 39,496, a mixed crowd that, by the end, had been drained of its Philadelphia influence.

Jayson Werth, the former Phillie and favored target of visiting fans, delivered the lodestone hit, a three-run home run with two outs in the fifth inning that gave the Nationals their first runs. Once Werth’s blast landed in the visitors’ bullpen, the levee broke. The Nationals bashed three homers and outhit the Phillies, 15-5, even as Bryce Harper went 0 for 4 with a walk. Grinning, 26-year-old left-hander Gio Gonzalez cruised, allowing one run on four hits and a walk in seven innings while whiffing seven Phillies and hitting a double himself.

Afterward, Werth gave an interview that blared throughout the park. “I’m just excited to send most of the people here home happy,” he said. During Manager Davey Johnson’s postgame news conference, a fan watching from the President’s Club tapped on a glass divider. “What was that?” Johnson asked, breaking into a grin. “A Philly fan?”

“It feels like they have a chip on their shoulder,” Phillies right fielder Hunter Pence said.

The Nationals spoke with reverence for the Phillies, the five-time reigning National League East champs. “It’s their division,” third baseman Ryan Zimmerman said before the game. “Someone has to take it from them.” Gonzalez added, “They’re champions for a reason.”

On the field, the Nationals brought defiance. They have clinched the weekend series and beaten the Phillies, going back to last season, seven consecutive games. Washington, having won four straight to stay in first place, leads the Phillies by 51 / 2 games. It’s not only a fair fight. It’s now a rivalry.

“That’s the beauty of it. Every year is a new year,” reliever Tyler Clippard said. “You’re already seeing it. Even before we played them, they were chasing us. It’s already changed. These first few games have been a good indicator of that.”

The Nationals and Phillies will meet 16 more times over the next five months, and with far different rosters. The Phillies played without Ryan Howard, Chase Utley and Cliff Lee while Zimmerman, Michael Morse and Adam LaRoche watched for the Nationals. Saturday, though, felt like a benchmark.

“I think all we’re doing right now is reaffirming that we can play with them,” Johnson said. “They’re short-handed, we’re short-handed, probably more so than them. But we can still compete with them. I think that’s a good message to send.”

Their latest victory over the Phillies happened because of the meeting’s most divisive figure. By the time Werth came to the plate in the fifth, he had batted during the series with eight total men on base. None of them had scored.

“I felt like I was trying to do too much,” Werth said. “My swings were a little big. Today, I was trying to be shorter, be quicker to the ball.”

Harper had just flown out to left, not quite deep enough to score Gonzalez from third base, for the second out. Werth took a slider for ball one from Phillies starter Vance Worley, and then Worley tried an 88-mph cutter inside — just the pitch Werth was looking for. He destroyed it. Werth jogged out of the batter’s box and, as the ball landed over the left field fence, flipped his bat toward the Nationals’ dugout.

“He needed one of those big blows,” Gonzalez said.

The crowd erupted, raw noise of all types. The cheers outnumbered boos by the time Werth circled the bases and slapped hands with teammates.

The Nationals led, 3-1. But they were not done. Chad Tracy and Danny Espinosa singled, and Rick Ankiel doubled to score Tracy and give them a 4-1 lead. Espinosa was thrown out trying to score, but that didn’t diminish Ankiel’s contribution. In the series, Ankiel is 6 for 8 with an intentional walk and two doubles.

Ian Desmond and Tracy delivered the knockout. Desmond clobbered a home run over the 402-mark on the center field fence. Tracy, who before Friday had not homered since 2010, blasted his second homer in as many days, a two-run shot into right field seats.“You see that guy in front of you go deep, and it just lets you know that this guy’s stuff is not that good today,” Tracy said. “He’s going to make mistakes. It pushes each other.”

The outburst had actually started with Gonzalez, who said throughout spring training what a terrible hitter he is. He smashed a double off the fence in right-center to lead off the fifth, smiling all the way to second. He took third on a grounder to second, flopping on his knees into the base.

“It was terrible,” Gonzalez said. “I turned to the dugout and the first thing I said was, ‘I’m going back to the American League, so I don’t have to slide anymore.’ That’s never going to happen again.”

The National League has suited his pitching fine. Gonzalez has allowed 13 hits in his past five starts, a span of 34 innings. “When he’s commanding,” one NL scout said, “he’s untouchable.” Saturday, Gonzalez threw 77 strikes out of a season-high 107 pitches.

In the bullpen, Clippard heard taunts from Phillies fans, but with less volume than usual. Werth estimated the crowd favored the Nationals 65 percent to 35 percent . Loud boos cascaded when the Nationals took the field, but cheers overtook them.

“It matters to a certain extent, for sure,” Clippard said. “It was frustrating being a team that was lower echelon and having your home park be bombarded by a visiting team and all that stuff. When you’re home, you want to be home. We didn’t really have that. This year, so far, so good.”

The Nationals will have a have a chance for the sweep Sunday night, their first game on ESPN’s weekly showcase since the night Nationals Park opened in 2008. They will take the field at 18-9, in first place, with the best starting rotation in baseball and the nation watching, wondering what is going on in Washington.

“I think everyone will recognize we’re for real,” Tracy said. “We know it. Now it’s just a matter of everybody else figuring it out.”