Pittsburgh, PA (Sports Network) - A day after being called back up to the big leagues, Alex Presley was the unlikely hero and the Pittsburgh Pirates moved back into first place in the NL Central.

Presley's walk-off single in the 11th inning was the difference, as the Pirates beat the St. Louis Cardinals, 2-1, in the opener of a doubleheader at PNC Park.

Russell Martin and pinch-hitter Gaby Sanchez each worked one-out walks off Kevin Siegrist (0-1). Presley hit a full-count fastball that deflected off Siegrist's glove and went past shortstop Pete Kozma to score Martin.

Vin Mazzaro (6-2) pitched a hitless 11th inning to earn the win for the Pirates, who took a half-game lead into the nightcap.