Geoff Blum doubled in three runs and the Houston Astros handed the Arizona Diamondbacks only their third home loss in 13 games his season, 6-4 on Tuesday night.

Hard-throwing Max Scherzer, Arizona's 2006 first-round draft pick out of the University of Missouri, made an impressive major league debut, to say the least, in relief of Diamondbacks starter Edgar Gonzalez.

Scherzer retired all 13 batters he faced, seven by strikeout, with a fastball that reached 98 mph on the Chase Field radar gun. It was the most strikeouts ever by an Arizona pitcher in his first big-league game.

Jose Valverde, who led the majors with 47 saves for Arizona last year and was traded to Houston in the offseason, pitched a scoreless ninth for his fourth save in seven opportunities.

The Astros ended Gonzalez's night with a four-run third inning that put Houston up 6-2. Blum drove in three with a bases-clearing double, then scored on J.R. Towles' double to left that replays showed should have been ruled a home run.

Gonzalez (1-2) allowed six runs on eight hits in 2 2-3 innings. Doug Brocail (1-0) threw 1 1-3 innings of scoreless relief to get the victory.

Conor Jackson had three RBIs, including a two-run homer, for Arizona.

Houston starter Jack Cassel allowed three runs on four hits in 4 2-3 innings, falling one out shy of being eligible for the win.

The Astros jumped on Gonzalez for two runs in the first. Michael Bourn singled, then scored from first on Miguel Tejada's double. Tejada scored on Carlos Lee's two-out single off the glove of diving first baseman Jackson.

Cassel retired the first two batters in the Arizona first and had an 0-2 count on Orlando Hudson before the second baseman singled. Jackson followed with a shot into the left field seats, his sixth home run of the season, to tie it at 2-2.

Arizona got a run in the fourth when Hudson tripled and scored on Jackson's ground out, and another to cut it to 6-4 on pinch hitter Miguel Montero's RBI single in the seventh.

Cassel singled with two outs in the second and tried to score from first on Kazuo Matsui's double. But Stephen Drew's relay throw from Jeff Salazar easily got their ahead of the runner to end the inning.

Tejada and Lance Berkman singled with one out in the third, then Carlos Lee walked to load the bases for Blum, who was batting .206 entering the game with three RBIs.

Notes:@ Arizona RHP Micah Owings (4-0), who sprained his ankle Friday in San Diego, will return to the Arizona rotation with a start Friday night against the New York Mets. ... Scherzer struck out 38 and walked three, allowing three earned runs, in 23 innings with Triple-A Tucson. ... Cassel was making his sixth start and eighth appearance in the majors. His brother Matt is backup quarterback of the New England Patriots.