Pierre, who became the Dodgers' starting left fielder when Manny Ramirez was suspended for 50 games, went 3-for-5 with a triple in the seventh and a two-run single in the eighth.
The offense was more than enough for Eric Milton (1-0) who won for the first time since Sept. 12, 2006. Milton, who sat out last season recovering from Tommy John surgery, went five-plus innings and gave up seven hits, but he struck out three and did not walk anyone.
Aaron Cook (3-2) gave up five runs -- four earned -- on eight hits over six-plus innings. Clint Barnes accounted for the only Rockies run with a fifth-inning home run.
After being held to one run in the first despite loading the bases with no outs, the Dodgers broke the game open in the fifth on Casey Blake's three-run double to make it 4-0.
The Dodgers added a run in the seventh when Orlando Hudson singled Pierre home from third. Pierre then drove in a pair of runs in the eighth with his RBI single.
Copyright 2009 by United Press International.