The Cardinals held their 3 1-2-game division lead over Pittsburgh.
Colorado lost all six games on its just-completed road trip.
Gonzales (3-2), in his fifth major league start, gave up one run on four hits and four walks over 5 2-3 innings. His strikeout total was the most by a Cardinals rookie left-hander since Rick Ankiel fanned 11 in 2000 against Pittsburgh.
Trevor Rosenthal struck out the side in the ninth to pick up his NL-leading 44th save in 49 opportunities. Six St. Louis pitchers combined to fan 16.
Peralta hit his team-leading 21st homer, a two-run shot in the third off Jordan Lyles (6-3).
