DETROIT -

Andy Dirks hit his first career grand slam, part of a six-run fourth inning for the Detroit Tigers in their 7-2 victory over the Houston Astros on Monday night.
   Victor Martinez also homered for the Tigers, who swept four straight from the Astros in Houston earlier this month and opened this three-game series at Comerica Park with another convincing victory.
   Anibal Sanchez (4-3) allowed two runs and six hits in seven innings for the Tigers. He struck out eight with one walk.
   Bud Norris (4-4) allowed seven runs and nine hits in five innings before leaving with lower back spasms. Houston has lost five straight and 15 of 18 -- and the Astros also lost standout second baseman Jose Altuve in the second inning with a jaw injury.
   Detroit trailed 2-1 when Martinez hit a two-run homer in the fourth to give the Tigers the lead. They weren't done. Jhonny Peralta and Don Kelly both singled with one out, and after a walk to Omar Infante, Dirks hit a drive over the wall in right field to make it 7-2.
   Dirks also doubled in the first inning and finished a triple shy of the cycle -- a fine performance in the leadoff spot after Austin Jackson went on the disabled list earlier in the day. Jackson, Detroit's center fielder and leadoff hitter, has a pulled left hamstring. Kelly started in center field Monday.
   Torii Hunter's double in the first scored Dirks to give the Tigers a 1-0 lead. Altuve left the game after colliding with right fielder Jimmy Paredes on a popup, but Houston scored a couple of runs in the third to take the lead. Marwin Gonzalez singled and stole second, then scored on a single by Robbie Grossman.
   Ronny Cedeno, who came into the game when Altuve left, added an RBI groundout.
   But Norris, who has pitched well so far amid Houston's struggles, couldn't hold onto the lead, and his start was cut short by back problems. He left the game after a conference at the mound at the start of the Detroit sixth.
   Martinez's homer was his second of the year after he missed all of 2012 with a knee injury.
   The Tigers have outscored Houston 44-10 in five games this year.
   NOTES: Detroit slugger Miguel Cabrera had his hitting streak snapped at 11 games. ... Tigers RHP Doug Fister (4-1) takes the mound Tuesday night against Houston RHP Lucas Harrell (3-3).