CINCINNATI -- Tommy Edman expected to see a breaking ball on the first pitch of his sixth-inning at-bat, and he didn't waste it.
"I figured Stephenson would try to spin me," Edman said. "I'd watched how he'd pitched to the other batters. He left one out over the plate."
The slam came one pitch after the Reds just missed what would have been an inning-ending double play. Stephenson retired pinch-hitter Yairo Munoz on a bases-loaded fly to right fielder Yasiel Puig, and Puig's throw home kept Matt Wieters at third. Catcher Juan Graterol's throw to first almost caught Kolten Wong off the bag, but Wong got his hand to the base a split-second before Joey Votto's tag. Votto had to scramble back to the bag from his cutoff position.
"Kolten got out there a little bit, but he could afford to do that based on where was," Cardinals manager Mike Shildt said.
Stephenson (2-2) allowed four hits and five runs while getting just two outs
"Robert was throwing strikes for the most part," manager David Bell said. "Robert's been pitching well. I would use him again in that spot. We don't want to rely on the same guys, and Robert has elite stuff."
Eugenio Suarez hit a solo home run in the first inning and added a sacrifice fly in Cincinnati's two-run third as the Reds built a 3-0 lead.
DeJong got St. Louis on the board in the fifth with his first homer since June 16 and 14th this season.
"That was a big swing," Shildt said. "We needed it. He needed it. It swung the momentum back to us."
Edman's blow gave Dakota Hudson the win. Hudson (9-4) gave up six hits and three runs with two walks and three strikeouts in five innings. He's 7-1 over his last 11 starts. Hudson also hit a batter.
Roark sparked their two-run third with a leadoff double. He pitched five innings, allowing five hits and two runs with two walks, a hit batter and six strikeouts -- three of Paul Goldschmidt, including to end the fifth with runners on first and third with two outs.
The Reds are 2-5 since the All-Star break and dropped eight games behind the NL Central-leading Chicago Cubs
Suarez celebrated his 28th birthday with his third first-inning home run in Cincinnati's last four games and major league-leading ninth first-inning homer of the season. Milwaukee's Christian Yelich and Baltimore's Trey Mancini each have eight.
Catcher Curt Casali on Thursday went on the 10-day injury list with a right knee sprain. Simultaneously, catcher Kyle Farmer went on the seven-day concussion list. The moves left Cincinnati with three catchers on the IL. Graterol was promoted from Triple-A Louisville on Wednesday, and the Reds signed Ryan Lavarnway a day after he was released by Yankees.
THAT WAS QUICK
The Cardinals' Edmundo Sosa got his first major league hit with a bloop single to right with one out in the ninth, but it became a double play when Puig threw Harrison Bader out trying to go first-to-third and Suarez threw out Sosa trying to advance to second.
Cardinals: C Yadier Molina will wait at least three weeks before his right thumb tendon strain is re-evaluated. Molina has been on the 10-day IL since July 8.
Reds: OF Nick Senzel is expected to miss a couple of days but avoid the IL after leaving Wednesday's game with right hamstring tightness. ... RHP David Hernandez was placed on the 10-day IL with right shoulder fatigue.
Cardinals: RHP Adam Wainwright's (6-7) 5.01 ERA in 30 career appearances against Cincinnati is his highest against any NL opponent.
Reds: RHP Tyler Mahle (2-10) set career highs by allowing 12 hits and 10 runs over 4-1/3 innings in his last start on Sunday at Colorado.
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