Nationals 2, Reds 1 (13): Jayson Werth's RBI single in the bottom of the 13th inning lifted first-place Washington to its fourth straight victory, and second extra-inning win in a row over Cincinnati.

With one out, Danny Espinosa reached on an infield hit, and Ryan Zimmerman and Adam LaRoche walked before Werth hit a 1-2 pitch up the middle off Sean Marshall (0-1).

Chris Stammen (2-0), the Nationals' sixth pitcher, struck out the side in the 13th. He was also the winner in Friday's 10-inning game.

The Nationals tied the game 1-1 on Xavier Nady's pinch-hit homer in the eighth inning.

Cincinnati's Bronson Arroyo allowed three hits, walked one and struck out four in 7 1/3 innings. He also hit a sacrifice fly in the fifth inning to give the Reds a 1-0 lead.

Arroyo was relieved by Bill Bray, who promptly allowed Nady's blast. Left fielder Ryan Ludwick had a chance to make the catch, but the ball glanced off his glove and continued over the fence.

Washington's Jordan Zimmermann allowed a run and three hits in seven innings and has yielded only three runs (two earned) in 14 innings in his first two starts.

Both teams had an excellent chance to score in the 12th. Washington's Tom Gorzelanny got out of a first-and-second, one-out jam by striking out Chris Heisey and Drew Stubbs. Roger Bernadina ran the Nationals out of the bottom half when he was caught by shortstop Zack Cozart taking a big turn around third following Wilson Ramos' ground ball and eventually tagged out in a rundown.

Arroyo hit a deep shot to center field in the fifth inning to score Willie Harris, who led off with a double. Arroyo also singled to center in the third for the game's first hit.

GAME NOTEBOOK: Cincinnati second baseman Brandon Phillips struck out pinch hitting in the 13th inning in his first appearance since signing a six-year, $72.5 million contract extension on Tuesday. Phillips had missed three games with a hamstring injury. ... The Reds' Scott Rolen went 0-for-5 and is off to a 3-for-26 start. ... Arroyo allowed five runs (four earned) and 10 hits against Miami in his first start of the season.