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Nathan Karns makes his second major league start on Sunday when the Washington Nationals complete their three-game series versus the Atlanta Braves at Turner Field.

Karns did not get a decision in his debut versus the Baltimore Orioles, as he allowed three runs and five hits - 2 HRs - in just 4 1/3 innings. He also walked a pair in his team's 9-3 loss.

"Everyone is going to be nervous for the first time," Karns said. "I was really anxious. I just hate sitting around waiting for my turn with the rain delay. It kind of made the buildup a little more. Once I got out there and got that first inning through, it felt great."

Atlanta, meanwhile, counter with lefty Paul Maholm, who is 6-4 with a 3.74 ERA. Maholm did not get a decision on Tuesday in Toronto and was not good. He allowed five runs and 10 hits in six innings of that one, a 7-6 Braves loss.

Maholm pitched well in a loss to the Nats earlier in the season, but is just 2-7 lifetime versus them with a 4.64 ERA in 12 games.

Atlanta evened this series on Saturday, as B.J. Upton drove in the winning run in the last of the 10th inning to lead the Braves to a 2-1 win.

With Henry Rodriguez (0-1) on the mound, Evan Gattis worked a walk to start the frame. After pinch-hitter Ramiro Pena fouled out on a bunt attempt, Gattis moved into scoring position thanks to a walk from Dan Uggla. Upton then stroked a single to right for the win.

Andrelton Simmons drove in the other run while Jordan Walden (2-1) worked a perfect top of the 10th to pick up the win for the Braves, who had lost four of six coming in. Tim Hudson gave up an unearned run on three hits and a walk with four strikeouts over 7 1/3 innings in the start.

"They're all big wins, but this rivalry between us and them is pretty intense," said Simmons. "It's a lot of fun playing against them. We always want to win on our home field, especially against these teams that are trailing us in the division."

Ian Desmond drove in the lone run of the game for the Nationals, who have lost 13 of 21 to fall 5 1/2 games back of the Braves in the NL East. Gio Gonzalez went seven innings and gave up just one run on three hits with a walk and seven strikeouts.

"The guys battled really hard and played their hearts out," said Gonzalez. "They were out there swinging and doing their best, but Hudson pitched a great game."

To make matters worse for the Nationals, the team placed slugger Bryce Harper on the 15-day disabled list because of bursitis in his left knee

"You always do what's best for the player," Nats manager Davey Johnson said. "If the club felt that he would be able to come back in three or four or five days, we wouldn't have DL'd him."

Atlanta is 10-3 in the last 13 matchups with the Nationals.