Griffey's 17th home run of the season came in a five-run Seattle fifth that also included an RBI sacrifice fly by Franklin Gutierrez and a run-scoring double by Bill Hall.
The outburst cleared the way for Felix Hernandez (18-5) to pitch into the eighth and win his sixth consecutive start. Hernandez allowed two runs on seven hits in 7 2/3 innings.
Kurt Suzuki drove in two runs in the ninth inning for the A's.
Trevor Cahill (10-13) took the loss after giving up six runs on eight hits in 4 2/3 innings.
Copyright 2009 by United Press International.