(Sports Network) - Veteran right-hander Tim Redding can make it six starts without a loss tonight when the Washington Nationals head to Pittsburgh to begin a three-game midweek series with the Pirates at PNC Park.

Redding, a 30-year-old native of Rochester, N.Y., is 2-0 with three no- decisions since dropping a 7-3 verdict to Florida on May 9 in Washington.

That loss came one start after Redding last met Pittsburgh and earned a victory after allowing six hits and a run in 6 1/3 innings of a 5-2 Nationals win on May 4.

In his last start, on June 5 against St. Louis, Redding allowed nine hits and six runs in 5 2/3 innings, getting a no-decision in Washington's 10-9 triumph.

The Nationals are 10-3 in games in which Redding had pitched in 2008.

For Pittsburgh, lefty Paul Maholm tries to reverse the outcome of a May 3 meeting with Washington.

In that start, on May 3, the 25-year-old former first-round draft choice was shelled for 10 hits and seven runs in five innings of a 9-8 loss.

He is 0-2 in three lifetime starts against the Nationals with a 6.38 earned run average.

Maholm is 2-0 with a no-decision in his last three starts overall, giving up 20 hits and eight earned runs in 22 2/3 innings.

On Monday in Pittsburgh, Luis Rivas drove in two runs and scored another as the Pirates earned a 5-3 victory over the Arizona Diamondbacks to gain a split of a four-game series.

Rivas was 2-for-3 and Doug Mientkiewicz scored twice as Pittsburgh won its second straight game.

Zach Duke (4-4) went six-plus innings to earn the win, allowing just two runs on five hits while striking out five.

In Washington, Randy Winn went 2-for-4 with two runs batted in, while Matt Cain tossed 6 1/3 strong innings as the San Francisco Giants edged the Nationals, 3-2, to complete a four-game sweep at Nationals Park.

Lastings Milledge scored a pair of runs for the Nationals, losers in eight of their last nine games. Jesus Flores drove in a run, while Cristian Guzman and Dmitri Young collected two hits apiece.

Tyler Clippard (0-1) was called up from Triple-A Columbus before the game and got the start, dropping the decision in his Washington debut after surrendering all three runs and five hits in 4 1/3 frames, striking out six and walking four.

Washington has won three of four from the Pirates this season.