Hernandez hit the first batter he faced this spring, then retired nine in a row. The right-hander threw 26 of his 35 pitches for strikes.
Seattle star Ichiro Suzuki went 3 for 3 with two RBIs.
Mat Latos, expected to serve as Cincinnati's No. 2 starter, allowed two hits in two scoreless innings in his spring debut. The Reds acquired the right-hander when they traded four players to San Diego in December.