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After compiling a career-high 21 wins last year, Gio Gonzalez has been through some rough patches already in 2013.

The left-hander aims to have a bounce-back performance Sunday afternoon when the Washington Nationals play the rubber match of their three-game series against the Pittsburgh Pirates at PNC Park.

Gonzalez has given up at least five earned runs on three occasions this season, more than he did for the entire 2012 campaign. He's coming off an 8-1 loss at Atlanta Tuesday. In that game, Gonzalez gave up seven hits and five runs, although he did fan a season-high nine in four innings.

During his career, Gonzalez has faced the Pirates twice and is 1-0 with a 2.77 ERA.

Wandy Rodriguez counters for the Pirates. The 34-year-old lefty is coming off a 10-4 loss in Milwaukee Monday night when he allowed six hits and seven runs in 4 2/3 innings. The Pirates have been victorious in four of his first five starts.

Rodriguez is 5-2 with a 4.50 ERA in 10 career starts against the Nationals. In his only start last year as a member of the Astros, he lost a 1-0 decision to Gonzalez at Nationals Park.

Tyler Moore's tie-breaking sacrifice fly in the top of the ninth inning helped send the Nationals to a 5-4 victory Saturday.

Wilson Ramos contributed a two-run single and both Adam LaRoche and Ian Desmond also had sac flies for Washington, which had lost four of six coming in.

Nationals starter Stephen Strasburg surrendered two-run homers to Starling Marte and Clint Barmes, but got through his final two innings of work unscathed. He matched a season-high with seven innings pitched and struck out eight while scattering five hits.

"The biggest thing was give your team a chance to win the ball game," Strasburg said. "Not every game is going to be lights out, just hitting every spot. I made a couple of mistakes."

Tyler Clippard (2-1) and Rafael Soriano each pitched a scoreless inning of relief, with Soriano notching his 10th save in the victory.

"We've played very good ball to this point," Pirates manager Clint Hurdle said. "Every once in a while you have a game where you're not in sync."

Since the 2001 Opening of PNC Park, the Nationals/Expos franchise is just 3-7-2 in series play in Pittsburgh. A total of 11 of the last 13 games between these clubs have been decided by two runs or less.