Hernandez (8-3) held the Dodgers to just one unearned run on four hits with nine strikeouts and one walk.
Griffey's homer was his ninth of the season and the 620th of his career.
Russell Branyan had a home run and a triple, Franklin Gutierrez had three hits and one RBI, and Ichiro Suzuki had three hits for the Mariners, who won for the sixth time in their last eight games.
However, the Mariners also learned Saturday that they will be without third baseman Adrian Beltre for at least six to eight weeks, announcing that he will undergo surgery to have bone spurs removed from his left shoulder.
Rafael Furcal had two hits and scored a run for the Dodgers, who have lost three of their last four games.
LA starter Eric Milton (2-1) took the loss, giving up four runs on seven hits with seven strikeouts and no walks in five innings.
Copyright 2009 by United Press International.