PITTSBURGH -- Matt Carpenter raced home to break a scoreless tie in the ninth inning when two Pittsburgh Pirates outfielders mishandled Jon Jay's single, and Mark Reynolds followed with a two-run homer to lift the banged-up St. Louis Cardinals to a 3-0 win on Monday night.

The Cardinals reduced their magic number to clinch a third straight NL Central title to two after getting to Pittsburgh closer Mark Melancon (3-2). St. Louis can wrap up the division with a victory at Pittsburgh Tuesday night.

In the bottom of the seventh, Cardinals outfielder Stephen Piscotty was carted off the field following a violent collision with teammate Peter Bourjos. The team said Piscotty was taken to the hospital with a head contusion, and all tests conducted were negative. He will be held overnight for observation.

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Carpenter singled with one out and scored all the way from first when Pittsburgh right fielder Gregory Polanco overran Jay's hit and center fielder Andrew McCutchen couldn't pick the ball up cleanly.

Reynolds then drilled his 12th homer of the year to give closer Trevor Rosenthal some cushion for his 48th save. Jonathan Broxton (4-5) earned the win.

Pittsburgh, already assured of a wild-card berth, left 16 runners on base while falling four games behind the Cardinals with five to go.

Pittsburgh has been relentlessly chasing frontrunning St. Louis for five months. Heading into the final week of the regular season, the Pirates finally had their chance to catch the Cardinals if they could earn a three-game sweep at home in a matchup of the teams with the two best records in the majors.

Instead, St. Louis did what it has done all year, relying on its pitching and just enough hitting to keep Pittsburgh at bay.

The Cardinals survived on a night they issued 10 walks. Pittsburgh put runners on base in every inning except the first, but none could find their way home on a night the Pirates went 0 for 12 with runners in scoring position, including 0 for 3 in the ninth with the tying run at the plate.

St. Louis starter Lance Lynn labored his way through five scoreless innings, most of them out of the stretch while the Pirates kept wasting opportunities to take control. Starling Marte was nailed at the plate to end the second while trying to score on a shallow fly to center by Jordy Mercer as Jason Heyward's throw beat the speedy Marte by three steps.

Marte then struck out with the bases loaded to end the third. Polanco led off the fifth with a double only to run into an out at third on a chopper to shortstop by Josh Harrison. Lynn needed 96 pitches to retire 15 batters, walking four with six strikeouts.

Pittsburgh starter J.A. Happ, a revelation since being acquired at the non-waiver trade deadline from Seattle, was decidedly more efficient. The lefthander allowed only Kolten Wong's single leading off the third.

Otherwise, he was dominant, striking out four and needing only 56 pitches to get through six shutout innings to lower his ERA to 2.04 in 10 starts with the Pirates. Happ was lifted for pinch-hitter Michael Morse with two outs and two on in the sixth. Morse walked to load the bases, but St. Louis reliever Seth Maness got Polanco to hit a routine fly to right to end the threat.

FRIGHTENING MOMENT

In a frightening scene during the seventh, Piscotty lay motionless on the grass in left-center field for several minutes after his collision with Bourjos. Piscotty, playing left, and Bourjos, playing center, were tracking Josh Harrison's drive to the gap when Bourjos' knee slammed into the head of the diving Piscotty. Bourjos made the catch while Piscotty crumpled to the turf.

Piscotty was strapped to a backboard and carted off the field. The rookie did manage a wave with his left hand before disappearing into a tunnel underneath the stadium, eliciting a big cheer from the Pittsburgh crowd.

TRAINER'S ROOM

Cardinals: C Yadier Molina's injured left thumb will keep him out for the rest of the regular season. Molina, who suffered a slight ligament tear in the thumb on Sept. 20, met with a hand specialist on Monday and will be given at least a week off before being re-evaluated. ... RHP Adam Wainwright, who tore his left Achilles tendon in April, could be ready to work out of the bullpen as early as Wednesday.

UP NEXT

The series continues on Tuesday when Michael Wacha (17-6, 3.15) faces Pittsburgh's Charlie Morton (9-8, 4.54). Wacha is 3-0 with a 1.93 ERA in six games against the Pirates. Morton is 2-11 in his career against the Cardinals, his last victory coming on April 4, 2011.