The Dodgers restored their lead over the Rockies in the National League West to three games, slowing down a Colorado charge by snapping the Rockies' four-game winning streak.
Ethier hit a two-run homer in the first and a solo shot in the fourth. Loney delivered a three-run blast later in the fourth.
In the last 13 games in which Ethier has had at least one at bat, he has hit .461 with four homers and 14 RBI.
Randy Wolf (9-6) took advantage of the home run support to win his fourth straight start. He allowed a run on five hits in 7 1/3 innings.
Los Angeles has defeated Colorado in 11 of their 14 meetings this season. Nevertheless, Colorado has charged into contention after being 15 ½ games out of first place in June.
Josh Fogg (0-2) took the loss, surrendering six runs on four hits in three-plus innings. Fogg made his first start since last September, when he was with Cincinnati.