The Rockies, who lost their 13th straight on the road, were missing left fielder Matt Holliday, right fielder Brad Hawpe and shortstop Troy Tulowitzki - who combined for 89 home runs and 352 RBIs and batted a cumulative .308 last season.
Lowe recorded 10 of his first 12 outs on ground balls, including a double play by Garrett Atkins, who drove in a run with a first-inning single. Lowe retired 21 of his last 25 batters before Scott Proctor finished up, allowing an RBI double by Yorvit Torrealba in the ninth.
Greg Reynolds (0-3) pitched five innings, allowing six runs - four earned - and seven hits including Kent's sixth homer and Ethier's fifth. It marked the fourth time in Reynolds' five big league starts that the 22-year-old right-hander gave up two home runs. In 28 1-3 innings overall, he has surrendered 18 earned runs, 25 hits and 18 walks.
Lowe, who had to settle for a no-decision last Wednesday at Chicago despite pitching seven scoreless innings against the Cubs, was staked to a 5-1 lead after three innings by a Dodgers offense that had averaged just 2.4 runs over its previous 10 games.
Ethier's first-inning groundout drove in Kemp, who doubled over the head of left fielder Ryan Spilborghs and took third on a wild pitch. Kent added his 371st career homer, breaking a tie with injured teammate Andruw Jones and Brooklyn Dodgers great Gil Hodges for 64th place all-time.
Los Angeles tacked on a pair of unearned runs in the second with the help of an error by third baseman Atkins, who fielded a grounder by Chin-lung Hu and threw the ball past second baseman Ian Stewart while trying to start a potential inning-ending double play. Danny Ardoin, who reached base on a walk, scored on Lowe's suicide-squeeze bunt, and Hu came home on Juan Pierre's single.
Ethier accounted for the Dodgers' fifth run with a leadoff homer into the right-field pavilion, his fifth of the season. James Loney made it 6-1 with an RBI single in the fifth and Kemp led off the seventh against Jorge De La Rosa with his fourth home run.
Notes: Lowe threw 110 pitches. He hasn't had a complete-game victory since June 22, 2006, when he beat Seattle 4-2 at Dodger Stadium. He went the distance three times last season - all resulting in losses. ... Reynolds was the second overall pick in the 2006 draft, five spots ahead of Dodgers LHP Clayton Kershaw, who will make his third attempt at his first big league victory in the finale of the three-game series. ... Spilborghs made the defensive play of the game, a sliding backhanded grab of Ethier's foul ball in the left-field corner with less than 10 feet separating the line and the field boxes. ... Lowe reached the 1,800-inning mark - and 1,800 hits allowed - both in the opening frame. ... Colorado is 18 games under .500 for the first time since finishing the 2005 season 67-95. The Rockies have lost 19 of their last 21 away from Coors Field.