DETROIT — Max Scherzer allowed three hits in a season-high eight innings and late substitute Don Kelly got the Detroit Tigers’ offense going Friday night in a 7-1 victory over the Seattle Mariners. Johnny Damon hit a two-run homer and the Tigers opened their homestand with a win despite playing without star slugger Miguel Cabrera, a late scratch from the lineup due to lower back pain. Cabrera began the day tied for the major league lead with 20 homers and 68 RBIs. Kelly, filling in at first base for Cabrera, doubled in Detroit’s first two runs in the second inning and Austin Jackson followed with a two-run single. Brennan Boesch added an RBI single in the fifth to chase Mariners starter Doug Fister (3-4), and Damon hit his fourth homer of the season off Sean White in the seventh. It was more than enough support for Scherzer (5-6), who struck out seven and walked two. The only run he allowed came on Franklin Gutierrez’s homer in the second. Scherzer hadn’t gone longer than 7 1-3 innings this season. Phil Coke worked a scoreless ninth. The Mariners, last in the A.L. West, came to Detroit after having won two of three at Yankee Stadium. Gutierrez didn’t start Thursday against the New York Yankees because of flulike symptoms. He entered that game in the seventh as a pinch-hitter.