Washington scored the game's first seven runs and won for the second straight night on the heels of a three-game losing streak.
Bernadina hit a two-run homer during a three-run first inning and also singled in a run in the second. Espinosa's two-run shot came in the third inning and Adam LaRoche also drove in runs with a double in the first and a single in the fourth.
Gio Gonzalez (4-1) survived five innings to get the victory, giving up two runs on five hits with four walks. He struck out nine, six of them coming in succession.
All of Washington's runs came against Mike Leake (0-5), who lasted only three-plus innings.