The night ended with the Cardinals enjoying a 4 1/2-game advantage over the Reds in the National League Central. Pittsburgh, mired in a three-game losing streak, sits 1 1/2 games behind.
"This is the team that I've seen for the bulk of this season," manager Mike Matheny said of his club, which has won 12 of its last 16. "This is the team that I believe these guys expect us to be every time we walk out of the dugout."
The Cardinals ambushed Mat Latos for two first-inning runs just 12 pitches into his start. That lead was fragile for much of Kelly's night, but the right-hander found a way to get through six innings despite constant traffic around him. The Reds provided an assist, too, when they ran themselves out of a run-scoring spot in the fourth.
"We've just got to play better baseball," Reds manager Dusty Baker said. "I'm really getting kind of tired of answering these questions every day for everything that happens and everybody. Sometimes a guy has to be held accountable for their actions. They're all big boys. They're all getting paid here. [The Cardinals] are beating us pretty good. We've got to change that."
The Reds swarmed the basepaths from the get-go. Kelly ended the first and second innings with runners on the corners. In the third, he needed a double play to erase a leadoff single.
Kelly faced another jam in the fourth, with two on, two out and Latos up. Latos laced a single -- his second of the game -- and Jay Bruce rounded third as if headed for home. Third-base coach Mark Berry chose instead to stop him, which proved costly when the trailing runner, Zack Cozart, didn't see Berry's hands go up.
Cozart continued for third, leaving Kelly to jog over and tag him as he and Bruce stood on the same base. The Reds, aside from Shin-Soo Choo's solo homer, would not advance another runner to third all night.
"That was a big part of the game," Cozart said. "I looked around and I saw [Berry] waving Jay home, so I started running to third. My focus went to seeing if he was going to cut the ball to [first baseman Allen] Craig. When I got to third, I was surprised Jay was even there."
Kelly went on to strand two more runners in the fifth, after allowing the homer. His last inning was his cleanest. Despite allowing a season-high eight hits, Kelly limited the Reds to one run.
"They are really good hitters," Kelly said. "Some guys with power, some guys with good averages, some All-Stars in there. You just try to go out there and make your pitch and have confidence in your pitch that you're going to make an out with it."
Kelly's ERA since sliding into the rotation is down to 2.24, and the Cardinals have won eight of his nine starts during that stretch. In six of those games, Kelly has exited having allowed one or fewer runs.
"He just keeps making good starts for us," said Matheny. "He's doing a great job."
A night after home runs accounted for seven Cardinals runs, the offense sank the Reds largely with a slew of singles. Of the team's 11 hits, only one -- Craig's RBI double in the sixth -- went for extra bases.
St. Louis opened the night with three straight singles. A slip and a bobble by two Cincinnati outfielders twice allowed the Cardinals to take an extra base, too. Matt Holliday drove home Matt Carpenter, helping him become the seventh player in franchise history to score 100 runs in a season.
For Holliday, it was his seventh straight game with an RBI. But the rest of his night would not be so enjoyable. Holliday fouled a pitch off his left foot, another off his left shin and was then hit on the arm by a 95-mph fastball. With the Cardinals comfortably ahead by the time of the eighth-inning plunking, Matheny pulled Holliday from the game.
"I'm pretty sore," Holliday said afterward.
After Craig's sixth-inning double pushed the lead back to two, the Cardinals used two singles and a Carpenter sacrifice fly to tack on a run in the seventh. Two more singles helped score two more in the eighth.
"Right now, every game is valuable for us," Beltran said. "We have to go out there and we have to take advantage of the situations the game [presents], so we have to be smart. I think we're doing that."
Before the Cardinals established enough of a lead to send closer Edward Mujica back to his bullpen seat, reliever Kevin Siegrist navigated through a tough part of the Reds' order to preserve a two-run advantage. Beginning with Choo and ending with Joey Votto, Siegrist struck out the side in the seventh.
Siegrist, who has an ERA of 0.64, has not been scored upon in 13 August appearances. His three strikeouts on Tuesday pushed that total to 40 in 28 innings.
"I'm happy with them," Siegrist said of his rookie-season numbers. "And I'm happy I can help out this team."
Trevor Rosenthal and Seth Maness followed with clean innings, as well.
"Lights out," Kelly said of the bullpen. "Look at those guys' numbers. They're pretty dang good back there."
The same could be said of Kelly since he left that group behind.