Xavier Nady tallied two RBI singles in support of Lincecum (10-14), who lasted 6 1/3 innings and scattered five hits.
Lincecum has allowed 11 earned runs in his last six starts. His win Tuesday cut San Francisco's magic number in the NL West to seven.
Marco Scutaro had three of the Giants' 12 hits, including an RBI single in the eighth inning.
Wilin Rosario homered for the Rockies, who have lost 11 of 13. Jeff Francis (5-6) lasted five innings, giving up two runs on six hits.