Lost in the loss, in Bryce Harper's walks and the Cubs' walk-off, was Tanner Roark outpitching Jake Arrieta Sunday afternoon, plain and simple.

The Nationals' right-hander did not factor in the decision; six innings of one-run work was undone by a Cubs rally against the bullpen in the seventh. But as Roark worked through the most productive lineup in baseball through six innings and did not allow a run, the right-hander impressed again, and lowered his ERA to 2.03 - the fifth-best in the National League as of Sunday night.

"We lost, so it doesn't matter what I did," Roark said. "It matters what the team does. We battled and scratched and clawed, but it is what it is."

That's Roark, generally deferential and team-oriented. But after being sent to the bullpen and being used in nearly every role imaginable last season, Roark showed a more overtly competitive side this year, too. Prior to this season, he said repeatedly that he wanted to start, that he thought he could be an asset as a starter - and that he wanted the chance to prove it again.

So far this season, and particularly Sunday against the potent and picky Cubs, Roark has not pitched like the affable, do-whatever guy he seemed during last year's chaos. He has attacked at all moments, for better or worse, challenging hitters, making them beat him. Sometimes they have. The Cubs put a runner in scoring position with fewer than two outs in five of the six innings Roark pitched Sunday. He allowed one run, an unearned one, when Ben Zobrist reached on an error and scored on a wild pitch. The key to holding a deep lineup like Chicago's down despite high-stress situations?

"Execute pitches. Bear down and don't give in," Roark said. "Once you give in, that's when they attack, so you just have to keep executing pitches and going after them."

Roark scattered four hits, walked two, and struck out seven in six innings. His pitch count rose as the Cubs worked him to deep counts, but when he got in those counts, he threw strikes. He relied on his two-seamer, which he painted on the outside corner time and time again, mixing it with a sharp curveball and solid slider and change-up that he threw for strikes. That mix has earned him a greater percentage of soft contact than any Nationals starter, according to FanGraphs.

"Soft contact" is a statistic calculated by Baseball Info Solutions (BIS), and is the most desirable of three categories of contact quality - soft, medium and hard. According to FanGraphs, no National League pitcher was inducing a higher percentage of soft contact than Roark, entering Sunday.

"Tanner was outstanding," Nationals Manager Dusty Baker said. "We would have loved to have got another inning out of him, but he had 106 pitches after the sixth. We had to go out there and get him. It was a tie ballgame, and we were hoping to get that pinch hit. Tanner's been doing his thing. If he keeps pitching like that, he's gonna win a lot of ballgames."

So far, however, Roark is 2-2, getting less average run support - fewer than 3.5 runs per nine innings - than any of the other Nationals starters. Sunday, he left the game having ensured the three runs he did get were enough. Though they did not remain that way, Roark's performance was nevertheless impressive. Charged with the task of hanging with Arrieta, the most dominant pitcher of the last half season or so, whose team had not lost any of the last 19 games he started, Roark nearly beat him. He is leading one of the National League's two best starting rotations in ERA, a so far unheralded ace.