DETROIT (AP) - 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.