DETROIT (AP) - Rick Porcello struck out 10 in six impressive innings, and the Detroit Tigers beat the Seattle Mariners 4-2 on Monday night to move a step closer to their third straight AL Central title. Victor Martinez broke a 1-all tie in the sixth with a run-scoring single, and Omar Infante followed with his own RBI single. Porcello (13-8) allowed a run and five hits with two walks, falling one strikeout short of his career high. Drew Smyly got five outs in relief and Jose Veras finished the eighth. Joaquin Benoit pitched a hitless ninth for his 21st save in 21 chances.