ST. LOUIS -- While refusing to disrespect the Astros by labeling this three-game series as a should-be sweep, the Cardinals nevertheless know the benefits of their schedule.
A current nine-game stretch against the Astros and Cubs presented the Cardinals with an opportune chance to create separation in their quest to lock down the second National League Wild Card spot. While closest competitors Los Angeles and Milwaukee still have games on the docket Thursday, the Cardinals depart St. Louis knowing that they've done their part.
The game wasn't crisp, nor was it all that well pitched or defended by St. Louis. But Houston's inability to capitalize helped the Cardinals finish off a three-game sweep with a 5-4 win over a team that has now lost 102 games. Six of those have come at Busch Stadium, where Houston went winless in 2012. This sweep runs the Cardinals' winning streak to four games and their lead over Los Angeles and Milwaukee, their closest pursuers in the NL Wild Card race, to three and 2 1/2 games, respectively.
"They're a big league ballclub, and anything can happen," said Carlos Beltran, whose two-run sixth-inning double became the game winner. "Thank God we were able to score early and make the plays and the bullpen was able to shut the door."
"We're really trying to just enjoy each one and realize how much we're putting on each game as a club," manager Mike Matheny said. "[We're] not looking forward to anything but the next one. I think the guys are staying pretty focused with that."
Cardinals pitchers stranded 11 Astros baserunners, including eight in scoring position. Houston loaded the bases in three innings but managed only one run out of those rallies -- a bases-loaded walk issued by starter Jaime Garcia in the first inning.
The Astros were hitless in five at-bats with the bases full.
"Those are professional hitters over there, guys who have been in the league eight to 10 years apiece who are going against first-year guys, guys with a month in the Major Leagues," Astros interim manager Tony DeFrancesco said. "So I'm not taking anything away from them, but that's the level we want to play at here, and we want to make some adjustments."
Whether the game is best described as being lost by Houston or won by the Cardinals is debatable. Regardless, several pitchers stepped up when the game was on the brink of unraveling.
First it was Garcia, who gave up just the one first-inning run despite allowing three of the first four batters to reach. Houston tied the game at 3 with a three-hit, two-run third off the lefty, but Garcia wrapped up his outing by stranding the go-ahead run at third in the sixth, his final inning, with a double play.
"It probably wasn't the best game I've felt physically, but at the same time, you have to keep battling," Garcia said. "You have to find a way to get it done and give the team a chance to win."
An inning later, another double play ended another bases-loaded threat by the Astros, this one against Edward Mujica.
Cardinals pitchers loaded the bases in the eighth, too, on three walks from relievers Mitchell Boggs and Marc Rzepczynski. Fernando Salas bailed his bullpen-mates out of that mess with back-to-back strikeouts to preserve a one-run lead.
"That's the game," Matheny said, pointing to Salas' work. "Salas came in and made great pitches."
Jason Motte, making his fifth appearance in the team's last five games, earned his 38th save in the ninth inning by stranding a runner at second. In all, the Cardinals held Houston to three hits in 14 at-bats with runners in scoring position.
Fortunate as the Cards may have been to escape with the victory, the manner in which the three-hour, 27-minute game progressed does lead to concern over the usage of the team's three best relievers.
Motte has pitched in six of the last eight days. Boggs appeared in all three games of this series after dealing with back tightness over the weekend. Since Aug. 12, Mujica has made 20 appearances. He has been scored upon in three of the last six, perhaps a warning of oncoming fatigue.
"We're very concerned," Matheny said when asked about that workload. "We'll have to adjust accordingly. We've talked about how important everything is right now; it calls us to the table. Fortunately, they have been feeling good every day, but that's not going to be able to continue. We're concerned."
The concern, though, isn't necessarily shared -- or at least admitted -- by those shouldering the load.
"If that phone rings, I'm going to bust my butt to do what I can," Motte said. "I know it's the same thing for every one of these guys. We don't shy away from anything. ... There's a difference between being hurt and being a little tired. I feel fine."
All of Houston's missed opportunities allowed for a pair of run-scoring hits by the Cardinals to stand as the difference.
The Cardinals led, 3-1, at the end of the first thanks to Allen Craig's three-run home run off starter Bud Norris. After the Astros evened the score, Beltran pushed Garcia in line for the win.
Matheny kept Beltran out of the lineup in a deliberate attempt to force the right fielder to rest. The intent, Matheny explained before the game, was to jump-start Beltran's production by keeping him fresh.
The payoff was immediate.
Summoned off the bench with two on and one out in the sixth, Beltran drove home both teammates with a sixth-inning double. It put the Cardinals ahead, 5-3.
"We need him," Matheny said of Beltran. "We've made no mistake about it. We knew that sooner or later, he'd come through."
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, and follow her on Twitter @LangoschMLB. This story was not subject to the approval of Major League Baseball or its clubs.