Cardinals 2, Giants 0: Acclaimed prospect Oscar Taveras homered in his second major-league at-bat and Michael Wacha pitched six strong innings as host St. Louis snapped a three-game skid.

Wacha (4-3) struck out seven and allowed three hits to improve to 4-0 in seven home starts this season. He had his day cut short by the second of two rain delays but combined with three relievers on a three-hitter.

Giants right-hander Yusmeiro Petit (3-3) turned in a strong outing in a spot start in place of Matt Cain but was tagged with the loss despite allowing just one run on two hits over six innings. San Francisco batters struck out 13 times as the Giants lost for only the second time in 10 games.

Petit retired the first nine batters before Matt Carpenter's leadoff single in the fourth. He sat down four more in a row before Taveras deposited a 1-0 offering into the right-field seats for his first big-league hit.

The Cardinals manufactured an insurance run in the seventh when Allen Craig led off with a single, stole second and scored on Jhonny Peralta's two-out double. Sam Freeman struck out two in a perfect seventh, Pat Neshek recorded a strikeout in a 1-2-3 eighth and Trevor Rosenthal struck out the side in order in the ninth for his 16th save.

GAME NOTEBOOK: The game was delayed twice because of rain with play halted for 47 minutes in the bottom of the fifth and for 51 minutes in the top of the seventh. … Carpenter was 1-for-3 to extend his hitting streak to 13 games and Giants 3B Pablo Sandoval went 1-for-4 to run his streak to 11. … Giants C Buster Posey (back) missed his third straight game.