The Cardinals improbably control their own 6, in the penultimate game of the regular season.
St. Louis trailed wild card-leading Atlanta by 10 1/2 games on August 25, but its recent 15-5 stretch, coupled with the Braves' swoon, evened the clubs' record at 89-72 with one game remaining. If a tiebreaker is needed, the Cardinals will serve as host on Thursday.
Allen Craig, playing as an injury replacement for Matt Holliday (hand), went 2-for-3 with a home run, three runs scored and four driven in for the Cardinals, who trailed 5-0 before rallying to keep its playoff chances afloat.
"There's a different story between tying and finishing it off, so we have another step," Cardinals manager Tony LaRussa said.
Enerio Del Rosario (0-3) was charged with three runs in St. Louis' game- changing four-run seventh to take the loss.
Rosario gave up a game-tying, RBI double to Craig and exited with two on and two outs. Wesley Wright entered from the bullpen and was greeted by Ryan Theriot's pinch-hit triple to the gap in right for an 8-6 edge.
Nick Punto knocked in Theriot with a double and added his first home run of the season in the ninth. Craig had extended the lead by that point with a three-run blast to left.
"They have guys on their bench right now that for a lot of teams would be playing," Astros reliever Wesley Wright said of St. Louis' depth. "They can take out guys and replace them with guys that are just as good if not better."
Eduardo Sanchez (3-1) earned the win in relief of Jake Westbrook, who was pounded for five runs on seven hits in just 2 1/3 innings. His counterpart, Henry Sosa, wasn't much better, surrendering five runs over 3 1/3 frames.
The Cardinals erased the deficit in the fourth, however. With the bases loaded and one out, Yadier Molina singled home a run and Skip Schumaker cleared the bags with a double to left-center before scoring on Jon Jay's sacrifice fly.
The Astros put their first three hitters on base in the fifth, only to get one run across on Paredes' double-play grounder.
Seven Cardinals relievers combined to allow just four hits in 6 2/3 innings...Punto had four hits and Lance Berkman added three in the Cardinals' 17-hit attack.