Mariners ace Felix Hernandez left after five innings as a precaution because of tightness in his right quadriceps. Seattle took a 7-3 lead into the ninth before Oakland rallied to tie it against closer Fernando Rodney.
Cruz connected off new A’s closer Tyler Clippard (0-1). Cruz led the majors with 40 home runs last year with Baltimore, then signed with the Mariners.
Rodney wound up with the win and Yoervis Medina finished for his first save in nearly two years.