Nationals starter Tanner Roark pitched eight scoreless innings, striking out 11 in a 6-0 victory over the Padres. (Gregory Bull/AP)

Every sector of the Washington Nationals has operated at full blast for the past week, but as they throttled another overmatched opponent Friday night, they only needed one pitcher. Their relievers took shelter in the bullpen. Their offense erupted, but every run that came after the game’s second batter proved cosmetic. All the Nationals required was the slightly stocky, out-of-nowhere starter who leads them in ERA. One of the hottest teams in baseball didn’t need anything more than Tanner Roark.

 At the end eighth inning of the Nationals’ 6-0 demolition of the punchless San Diego Padres, Roark walked into the third base dugout and bumped fists with coaches and teammates. “Hell of a job,” defensive coordinator Mark Weidemaier told him. He could celebrate one of the best games he ever pitched, one of the most dominating starts in the Nationals’ brief history. Roark struck out 11, walked none and allowed three hits over eight scoreless innings.

 “He’s been pitching like that for us all year,” Manager Matt Williams said. “Just continues to pound the zone, all of his pitches. Pretty impressive.”

 The Padres have scored the fewest runs in the majors, and earlier this season Roark had fired a shutout against them at Nationals Park. But a favorable matchup made his dominance no less impressive. It could not diminish the fact that Roark, a late-blooming 27-year-old, provided more evidence his ascendance cannot be considered a fluke. As he led the Nationals to their sixth win in seven games, Roark lowered his ERA to 2.91.

 “Everything felt good coming out,” Roark said. “I wasn’t holding anything back. I’m not trying to make perfect pitches. I was just throwing it, letting it go. If the hitter sees the same arm action on my fastball, you get ’em. … I don’t try to strike guys out. I just try to make good, quality pitches. Strikeouts happen.” 

Saturday, Blake Treinen will complete one cycle through the Nationals’ rotation. The last four starters have struck out 31 batters and walked one. Those four starters have also been supported by 25 runs. In the entire major leagues, only the Oakland Athletics, San Francisco Giants and Toronto Blue Jays own a better run differential than the Nationals’ plus-33. The Nationals do not own the record of an elite contender, but they are trending in that direction.  

“You definitely feed off it, for sure,” Roark said. “The rotation is doing so well. The relievers are doing so well. The bats are coming alive. It just gives you that much more confidence. You know we’re going to score runs.”

“You want to catch fire,” said right fielder Jayson Werth, who received the night off. “You got to rattle off some games. We got a good start there. This could be a good road trip for us. It’ll be a good test.”

The Nationals absorbed, and then dodged, one cause for worry. On his 24th birthday, after he bashed a two-run homer in the first inning, third baseman Anthony Rendon exited in the sixth after a chopper struck his hand. But X-rays came back negative, Manager Matt Williams said, and Rendon is considered day-to-day.  

 “Pretty worried” at first, Rendon said. “I didn’t really feel it. It just went straight to numbness. I’ll be alright.”  

 “It’s pretty swollen,” Williams said. “We’ll see how he feels tomorrow. We don’t want any more thumbs. It’s good news that it’s negative.”

Roark softened the blow of potentially losing Rendon. He dotted his two-seam fastball at the edges of the strike zone, both sides of the plate, unafraid to throw it at the letters or the knees. He did not plan to throw almost exclusively two-seamers and change-ups, but he located both pitches so well that catcher Wilson Ramos saw no need to use more than a smattering of curves and sliders.

 “When his sinker works, we can do everything we want,” catcher Wilson Ramos said. “We stayed on the same page tonight.”

 In 2012, Roark went 6-17 at Class AAA Syracuse. Now he has a sub-3.00 ERA in his first full major league season. A legitimate big league starter fell out of the sky and into the Nationals’ rotation, and they owe him only the league minimum until 2017. Nothing became a controllable, successful starter, only one of the most valuable assets in baseball.

 “Even in a hitter’s count, he doesn’t give you much,” Padres first baseman Yonder Alonso said. “He’s not on the white part. He lives on the black, and he’s got late life.”  

The Nationals offered more support than he needed. Denard Span led off with a walk, and Rendon came to the plate. The birthday boy fell behind, 0-2, after Ross started the at-bat with a pair of sliders. Rendon took two balls, and Ross threw him a thigh-high fastball over the plate’s heart. Rendon unleashed his swing, a clean whip of the barrel. The ball rocketed off his bat and landed in the upper deck in left field, some 425 feet from home plate, his fourth homer in seven games. Instantly, the Nationals led, 2-0.

 But after Rendon pummeled Ross’s mistake, Ross shut the Nationals down. Danny Espinosa led off the fifth inning with a triple on a laser into the right field corner. But Nate McLouth made a crucial out when he tapped back to Ross. The Nationals then needed the pitcher to put a ball in play, but Roark struck out. The needed a two-out hit, but Span lined out to left. They had stranded Espinosa at third.

 It was the kind of wasted opportunity that, without fail, doomed them throughout May. Friday night, the Nationals redeemed themselves with force and immediacy. The very next inning, the Nationals knocked out Ross and romped their way to another blowout.

 In the sixth, Ryan Zimmerman sparked a rally with an innocuous play – Ross scooped his dribbler, but fired wide of first and pulled Yonder Alonso off the base. After LaRoche walked, Ramos pounded an RBI ground-rule double over the right-field wall. Ian Desmond drew another walk, and Espinosa took a slider off his left knee to painfully force in another run.

 “Right off the corner of the kneecap,” Espinosa said. “It was a good one.”

 McLouth had cost the Nationals, but with the bases still loaded, he rolled a slider through the drawn-in right side of the infield. Two more runs had scored

 “Our lineup can be pretty dynamic,” Werth said. “If everybody is going, we got a chance to score a bunch of runs. We've got some weapons.” 

Friday night, Roark rendered those weapons a luxury.