Pirates 2, Cardinals 1: James McDonald tossed six scoreless innings on two extra days’ rest as visiting Pittsburgh took the opener of a three-game series critical to the NL wild-card race.

McDonald (11-5), who entered with an 8.71 second-half ERA, allowed just two hits while walking three and striking out seven.

The Pirates, who came in with a one-game lead over St. Louis and San Francisco for the second wild-card spot, won for just the third time in nine games. The Cardinals lost their second straight after a 2-0 start to their nine-game homestand.

The Pirates scored twice in the fourth without an RBI. Travis Snider walked, Andrew McCutchen and Garrett Jones singled, and Snider scored on Jake Westbrook’s wild pitch.

Shortstop Rafael Furcal couldn’t cleanly handle Mike McKenry’s grounder, loading the bases again. McCutchen scored on Tony Cruz’s passed ball.

The Cards cut the deficit in half in the seventh when Carlos Beltran singled, advanced on David Freese’s double and scored on Cruz’s groundout.

Pittsburgh's Jason Grilli pitched a perfect eighth and Joel Hanrahan worked around a ninth-inning walk to earn his 34th save in 37 chances.

Westbrook (12-9) gave up two runs (one earned) on six hits over 7 2/3 innings to fall to 1-6 lifetime against the Pirates.

GAME NOTEBOOK: Cardinals C Yadier Molina (sore back) and Pirates 2B Neil Walker (dislocated finger) sat out. … Jones made a diving stop to rob Jon Jay of a sixth-inning hit. … Cards third base coach Jose Oquendo was ejected in the sixth by home plate umpire Lance Barrett for arguing balls and strikes.