PITTSBURGH (AP) -- Pedro Alvarez homered twice and drove in four runs, James McDonald scattered two hits over seven innings and the Pittsburgh Pirates beats the St. Louis Cardinals 9-0 on Tuesday night.
Alvarez hit a two-run homer in the third to give the Pirates a comfortable lead, added an RBI double in the fourth then hit a 469-foot blast to center in the sixth. He went 4 for 5 as Pittsburgh drew within two games of the Cardinals in the race for the NL's second wild-card spot.
McDonald (12-6) gave up two hits, walked one and struck out six to beat the Cardinals and Jake Westbrook (13-10) for the second time in the last two weeks.
The Cardinals played most of the game without catcher Yadier Molina, who suffered neck, back and shoulder injuries following a violent collision at home plate with Pittsburgh second baseman Josh Harrison.
Harrison was attempting to score on a single to right field by Jose Tabata with two outs in the bottom of the second when he lowered his left shoulder and drilled Molina in the head as the catcher blocked the plate. The four-time All Star tumbled backward but held onto the ball, ending the inning.
It also ended his night.
Molina slowly got to his feet and made his way to the dugout before being diagnosed with a strained neck among other bumps and bruises. Tony Cruz replaced Molina when St. Louis returned to the field in the bottom of the third. Molina was listed as day-to-day.
While Harrison's hit failed to produce a run, it appeared to provide a spark for the Pirates, who came in losers in six of seven. Alvarez put the Pirates up 3-0 in the third with his 24th homer of the year and Pittsburgh poured it on in the fifth, sending 10 batters to plate to chase Westbrook.
Alvarez got things going with an RBI double to score Andrew McCutchen and Mike McKenry added a run-scoring single to make it 5-0. Westbrook exacted a little payback by drilling Harrison in the leg with a fastball, drawing a warning to both dugouts from home plate umpire Adrian Johnson.
By then, however, the damage was done, and when Clint Barmes followed the plunking with a two-run single the Pirates were up 7-0.
That was more than enough for McDonald.
The right-hander has struggled since the All-Star break but for a night returned to the form that made him one of baseball's biggest surprises during the first half of the season. He had little trouble against the Cardinals' surging lineup, surrendering a two-out single to Molina in the second and a two-out double in the sixth.
Other than that McDonald was flawless, allowing Pittsburgh's weary bullpen to get a needed break.
The Cardinals didn't get a runner to third base until the eighth while getting shut out for the second time this month and the seventh time this season.
Westbrook has been a key part of the Cardinals' rise during the second half of the season. He came in with wins in six of his previous seven decisions, but could do little as the Pirates snapped out of their swoon in a big way.
The veteran right-hander gave up seven runs and 11 hits in five innings, tying a season high with four walks while striking out just two. He threw just 61 of his 103 pitches for strikes.
NOTES: The series wraps up on Wednesday in the final meeting between the clubs this season. Joe Kelly (4-5, 3.26 ERA) starts for the Cardinals against Pittsburgh's Wandy Rodriguez (8-13, 4.01).