Tanner Roark outpitched Jordan Zimmermann by a wide margin today. Baseball can be a funky game. Making his major league debut, Roark, who was called up from Triple-A Syracuse yesterday, pitched two scoreless innings, keeping this game tied 2-2. Roark worked a 1-2-3 fifth inning, his first in relief of Zimmermann (who left after allowing seven hits over four frames), and after surrendering a leadoff bloop single in the sixth, the right-hander needed just two batters to get out of the inning. He got Andrelton Simmons to pop out to short and then made a diving grab of a Kris Medlen bunt attempt. From his knees, Roark doubled B.J. Upton off first to end the inning. All-in-all, a heck of a major league debut for the 26-year-old Roark, who was acquired by the Nats in July of 2010 in the Cristian Guzman deal. Roark's outing was much-needed for the Nats, who are still in this game going to the seventh despite an awful first few innings. Update: With Roark due up leading off the sixth in a tie game, Davey Johnson opted to pinch-hit for the rookie pitcher, bringing in Roger Bernadina to hit against the righty Medlen. Bernadina popped up to third on the first pitch he saw. That left Johnson needing to go back to his bullpen, and Fernando Abad couldn't keep the game tied. The left-hander served up a solo bomb to Justin Upton - his second go-ahead homer of the series - that gave the Braves a 3-2 lead. The Upton homer was an absolute missile and it left the yard in a hurry. The Nats now trail again, and the time for the filthy back-end of the Braves' bullpen is quickly approaching. Update II: It wasn't a hit with a runner in scoring position, but it still got the tying run in. Ian Desmond's fielder's choice groundout with one out in the seventh brought in Jayson Werth with the game-tying run, making it a 3-3 ballgame. It sounded like Desmond broke his bat on his slow roller to short, and he booked it out of the box, sprinting down the line to beat out the potential 6-4-3 double play to keep the inning alive and allow Werth to score. Adam LaRoche should also be credited with a nice, hard slide to help throw second baseman Dan Uggla off and not allow him to fully step into his throw to first. Ryan Mattheus will start the eighth inning for the Nats, who twice have come from behind to tie the game tonight. Update III: What an ugly top of the eighth it was for the Nats, who now trail 6-3 with six offensive outs separating them from a three-game sweep at the hands of the Braves. After Dan Uggla and B.J. Upton were retired by Mattheus to start the eighth, five straight Braves hitters reached base. Simmons doubled and Joey Terdoslavich walked, and after Johnson went to left-hander Ian Krol to face the left-handed-hitting Jason Heyward, things got bad in a hurry. Krol got ahead of Heyward 0-2, but got too much of the plate with a breaking ball, and Heyward lined it into right for an RBI single. Justin Upton then followed with a two-run double into the left field corner, making it a 6-3 game. All the while, Tyler Clippard was standing in the Nats' bullpen. It's easy to say this in hindsight, but I wonder if Johnson is second-guessing himself for not having Clippard start the inning. Update IV: That'll do it. The Nats lost 6-3, were out-hit 15-4 and were dropped their third straight to the Braves, wrapping up an Atlanta sweep. Harper and Werth reached to start the bottom of the ninth against Craig Kimbrel, but LaRoche and Desmond struck out, and after a Rendon walk, Wilson Ramos lined out to right to end it. The Braves have now won 13 in a row, are 10-3 against the Nats and are 6-0 at Nats Park this season. The Nats, meanwhile, are six games under .500, 15 1/2 back in the division and nine games back of the Reds for the final NL Wild Card spot.