Hernandez broke out of a 1-for-23 slump with home runs in his first two at-bats, lifting the Dodgers to their 11th straight win and 31st victory in 35 games.
The game was called in the top of the eighth inning after a 37-minute delay.
Hernandez had solo home runs in the second and fourth innings, his second career multi-homer game.
Chicago starter Carlos Rodon (1-3) allowed home runs to his first batter, as Chris Taylor led the game off with one, and his last, as Corey Seager's two-run homer in the fourth chased him.
Seager's blast was his 44th as a shortstop, passing Rafael Furcal for most career homers from the position in franchise history.
