(My Sportsbook) - With pennant races heating up during the latter stages of the regular season, there is no better time than now for New York Mets ace Johan Santana to get on a roll. He leads the National League East-leading Mets tonight in the opener of a four-game series versus the Houston Astros at Shea Stadium.

Santana had lost three straight starts to close out the month of June, but has since gone 4-0 with a 2.27 earned run average over his last nine outings. Santana tossed his first shutout as a Met in his latest start Sunday at Pittsburgh, yielding just three hits with seven strikeouts and no walks in a 4-0 win.

He is now 11-7 with a 2.75 earned run average in 26 starts in 2008.

The left-hander and two-time American League Cy Young Award winner will face Houston for the second time this season. Santana did not record a decision on August 2 at Minute Maid Park in a 5-4 Mets loss, although he allowed just a run and three hits in 6 1/3 innings of work. He is 1-0 with a 1.59 ERA in two career games (1 start) against the Astros.

New York will try to maintain its lead in the NL East on Friday and has won three straight after a sweep of Atlanta. The Mets have also won nine of 10 and 12 of their last 15 games.

In Thursday's 5-4 victory over the Braves, Carlos Delgado singled home the winning run in the ninth and finished 5-for-5 with three RBI. David Wright had three hits, including a home run, and scored three times for the Mets, who took advantage of Philadelphia's loss to Washington Thursday night.

Luis Ayala tossed 1 1/3 scoreless innings of relief for the win, while starter Pedro Martinez was reached for four runs in seven innings in a no-decision.

Houston has lost four of its last six games, including Wednesday's 5-2 setback to the Milwaukee Brewers in the finale of a three-game series at Miller Park. Wandy Rodriguez absorbed the loss despite a solid start, pitching 5 1/3 innings and surrendering three runs -- two earned -- on three hits, while striking out six and walking five.

Geoff Blum went 2-for-4 with an RBI and Miguel Tejada added two hits and a run scored for Houston, which will send ace Roy Oswalt to the hill in Friday's series opener with the Mets.

Oswalt has won three straight starts and is 5-0 with a 2.93 earned run average over his last seven outings. In his most recent performance Sunday versus Arizona, Oswalt hurled eight shutout innings of one-hit ball with 10 K's and a pair of walks to improve to 11-8 in 24 starts this season.

The right-handed Oswalt faced Santana and the Mets on August 2 and did not factor in the outcome of the Astros' 5-4 victory. Oswalt gave up four runs and six hits in six innings of that game, and is 5-4 with a 3.71 ERA in 12 career appearances versus New York.

Houston swept that three-game home set with the Mets and has won four of the last seven matchups in this series.