Diaz, with heavy heart, powers Cards past Reds 12-5

Diaz honors Fernandez with grand slam (0:29)

After spending recent days in Miami mourning the loss of Jose Fernandez, Aledmys Diaz hits a grand slam in the fourth inning that boosts the Cardinals to a 5-2 lead on the Reds. (0:29)

ST. LOUIS -- Playing with a heavy heart, Aledmys Diaz hit his first career grand slam and the St. Louis Cardinals finished with five home runs Tuesday night in a 12-5 victory over the Cincinnati Reds.

Chasing the Giants and Mets in a tight race for the two NL wild cards, St. Louis moved within a half-game of San Francisco for the league's final playoff spot -- pending the Giants' late game against Colorado.

New York, which beat Miami 12-1, leads the wild-card standings and remained 1 1/2 games ahead of the Cardinals.

Jhonny Peralta had a three-run homer and drove in four runs for the Cardinals, who had lost four of five. Matt Carpenter, Randal Grichuk and Matt Adams also homered.