Besides Ethier's career-best 29th homer this season the Dodgers got two RBI on a 3-for-4 performance by Orlando Hudson as Los Angeles won for the fifth time in seven games to hold a four-game lead over Colorado in the National League West.
Winning starter Jon Garland (10-11) allowed just two runs on six hits and three walks through six innings. Hong-Chih Kuo, George Sherrill and Jonathan Broxton each threw a scoreless inning in relief.
Daniel McCutchen (0-2) surrendered four runs on seven hits and two walks in five innings for the Pirates, who have lost six of seven.
Manny Ramirez doubled in a run and Doumit added a groundout RBI.