(My Sportsbook) - Washington lefty John Lannan tries for his first win of 2009 in his sixth effort of the season tonight, when the Nationals host the Houston Astros in the first of an abbreviated two-game series at Nationals Park.

The Nationals are 0-5 in games started by the 24-year-old New York native, in which he's pitched at least six innings three times and struck out 18 batters in 27 1/3 innings.

He fell to 0-3 in his most-recent start on April 28 at Philadelphia, losing a 7-1 verdict while giving up nine hits and three earned runs in five innings.

Lannan beat the Astros in his lone opportunity last season, scattering seven hits and allowing a run in six innings.

Veteran righty Brian Moehler returns from the disabled list for his first start for Houston since April 13.

A 37-year-old native of North Carolina, Moehler was roughed up for 15 hits and 12 runs in just four innings of work in his first two starts on April 8 and 13, before hitting the 15-day DL with a knee problem.

Subsequently, he gave up eight runs on 11 hits while throwing 90 pitches in a rehab start against Double-A Midland last week.

Moehler last faced the Nationals in 2007, pitching three innings of scoreless relief over two appearances while allowing three hits and striking out one.

On Sunday in Atlanta, Michael Bourn went 3-for-4 with two runs scored and a run batted in, as the Astros snuck past the Braves, 7-5, in the rubber match of a three-game set at Turner Field.

Carlos Lee went 1-for-4 with two RBI and a run scored for the Astros, who have won five of their last seven games. Miguel Tejada went 2-for-4 with an RBI. Lance Berkman, Ivan Rodriguez, and Geoff Blum each had an RBI.

Wandy Rodriguez lasted five frames, allowing three runs on six hits with three strikeouts and three walks in a no-decision for Houston.

Geoff Geary (1-3) allowed one run on three hits in 1 1/3 innings of relief to pick up the win. LaTroy Hawkins retired the side in the ninth to collect his third save of the year.

In Washington, the finale of a four-game set between the St. Louis Cardinals and the Nationals was postponed due to heavy rain.

The Nationals did not immediately announce a makeup date.

Washington won four of its six meetings with the Astros last season.