Pirates 9, Cardinals 0: Pedro Alvarez continued his assault of St. Louis pitching with two tape-measure homers and four RBIs, and James McDonald pitched seven shutout innings as host Pittsburgh won for just the second time in eight games.

Alvarez went 4-for-5 and fell a triple shy of the cycle. He hit a 422-foot two-run homer in the third and a 469-foot solo shot over the center-field stands in the sixth, the longest homer by a Pirate in 11 seasons since the opening of PNC Park.

McDonald (12-6) allowed two hits, one walk and struck out six to stifle St. Louis, which lost for just the second time in eight games.

Alvarez also had a run-scoring double off the base of the right-field fence in the fifth. He has six homers and 20 RBIs in 14 games against the Cardinals this season.

Alvarez’s first homer gave Pittsburgh a 3-0 lead. His double started a four-run fourth-inning assault against Jake Westbrook (13-10) in which the Pirates sent 10 men to the plate. Michael McKenry had a run-scoring single and Clint Barmes had a two-run single.

Alvarez’s epic sixth-inning blast came against Cardinals reliever Brandon Dickson. It sailed over the center-field stands and bounced out of the ballpark and onto the river-side walkway.

Travis Snider’s added a run-scoring triple to right-center in the seventh.

Westbrook allowed seven runs and 11 hits in five innings to lose for only the second time in eight decisions. Both losses have been against Pittsburgh.

GAME NOTEBOOK: Pirates 2B Neil Walker (back) missed his second consecutive contest. … Cardinals 3B David Freese (wrist) went 0-for-3 in his return to the lineup after missing three straight games. … McDonald pitched seven innings for the first time since defeating the San Francisco Giants on July 7. … Both teams were warned after Westbrook hit Josh Harrison with a pitch in the fifth.