Tossing a career-best 6 2/3 innings against the Mets on Monday, Kelly got his fifth win of the season, allowing just two runs on five hits.
Much of Kelly's effectiveness came from his ability to throw his sinker for a strike.
"That's what everyone else does on the staff," Kelly said. "That's kind of the way I pitched and how I came up through the system. I kind of shied away from it when I got here, but it worked for me."
He'll look to take that momentum into Sunday's series finale against the Brewers at Busch Stadium.
Losing its last two games to Milwaukee, St. Louis will also try and pad its lead for the second National League Wild Card spot, with the Dodgers just a 1/2 game behind.
Meanwhile, Shaun Marcum will take the hill for the Brewers, making his fourth start since coming off the disabled list. He's 0-1 with a 4.30 ERA since being reinstated.
The right-hander took a no decision in his previous start against the Marlins, surrendering four runs on seven hits in 5 2/3 innings.
Efficient with his 86 pitches, the right-hander still struggled with his command at points during the start.
"I'm getting there," Marcum said after the outing. "I'm feeling good when I start. It's going to get better with location. I'm missing location way too much right now. I'm giving these guys a chance to win. That's the most important thing."
Brewers: Parra OK after being hit by line drive
Brewers reliever Manny Parra said he "felt lucky" to have suffered only a black eye and swollen left cheek after being struck in the face by an Adron Chambers comebacker during Friday's win over the Cardinals.
With two outs in the ninth inning, Parra was struck in the face, before the ball deflected to first baseman Corey Hart, who touched first base for the inning-ending out.
"He took a pretty good shot," manager Ron Roenicke said of Parra. "We were just talking about it, and I can't believe the ball ricocheted that far off a cheek to where our first baseman can get an out on it. That's a long ways over there. He had stitch marks on his cheek."
Cardinals: Beltran out of starting lineup
With Carlos Beltran slumping at the dish, Cardinals manager Mike Matheny had him out of the starting lineup for Saturday's contest against the Brewers. However, Beltran did pinch hit in the game, popping out to shortstop in the bottom of the eighth inning.
Beltran, who is bothered by a sore left hand and an aching left knee, went 0-for-5 in Friday's 5-4, 13-inning loss to the Milwaukee Brewers. He is hitless in his last 14 at-bats and hasn't had an extra-base hit in 49 trips to the plate.
"There have been some physical things that have been bothering him and sometimes those lead to mechanical adjustments, more than are necessary," Matheny said.
The Brewers are 56-22 this season when scoring at least four runs.
Marcum is 1-1 with a 4.15 ERA in four career starts against the Cardinals, all of which came last season.
Center fielder Jon Jay is hitting .429 (9-for-21) during the Cardinals current six game homestand.