Friedrich (1-0), called up from Class AAA Colorado Springs Tuesday, was sharp in his initial appearance. The 24-year-old left-hander yielded two runs (one earned) on five hits while striking out seven and issuing only one walk.
He spotted San Diego a 2-0 lead before the Rockies came back to score the next six runs.
After Jason Giambi's fourth-inning RBI double shaved the Rockies' deficit, Colorado erupted for four unearned runs in the sixth, highlighted by Wilton Rosario's two-run two-bagger.
Chris Nelson added two RBI for the Rockies, who avoided a three-game sweep at San Diego.
Padres starter Anthony Bass (1-4) was victimized by shortstop Andy Parrino's sixth-inning error. Only one of the five runs he yielded on nine hits over 5 2/3 innings was earned.
Yonder Alonso and Jesus Guzman each had an RBI for San Diego.