It had already been an emotional day for the Nationals when they took the field at 7:05 p.m. with two pregame ceremonies honoring the victims of yesterday’s Navy Yard shootings and a visit from Admiral James Winnefeld vice chairman of the Joint Chiefs of Staff. Throw in their come-from-behind walk-off win in Game 1 of the day-night doubleheader and the Nationals were plenty exhausted before Game 2 even began. Then Tanner Roark took the mound and re-energized everyone in the ballpark. The rookie tossed seven scoreless innings allowing only two hits in his latest dominant performance. The Nationals gave Roark one early run which stood as the only one of the game until the eighth when they exploded for three huge insurance runs including Ryan Zimmerman’s latest homer. Rafael Soriano entered in a non-save situation and immediately got himself into trouble but battled through it to earn the save and sweep the doubleheader. The Braves now can’t clinch the NL East in D.C. but the Nationals will likely remain 4 1/2 games behind the Reds (winning big in Houston) for the final Wild Card berth with only 11 games left on the schedule. Hitting highlight: Though they scored three insurance runs in the bottom of the eighth let’s focus on the Nationals’ first run of the night which looked like it would have to hold up throughout the game. Bryce Harper led off the bottom of the second with a base hit to left then stole second off Freddy Garcia. Ian Desmond’s drive to left only reached the warning track for the first out but Adam LaRoche followed by drawing a walk. That set the stage for Steve Lombardozzi who poked Garcia’s pitch to right field. Harper came charging around third and scored giving the Nationals a 1-0 lead that remained until the eighth.