He mostly pitched out of trouble in the first four innings, allowing just one of 11 runners to score. But he was tagged for Joey Votto's two-run double in the fifth and, one batter later, David Ross' two-run homer.
"He made some good pitches to get out of innings," manager Tony La Russa said. "That one inning he didn't make them."
Wells took over the National League lead in losses at 17.
"It's not the first time that I've gotten hit around early in a game," Wells said. Actually, 53 of the 111 runs Wells has allowed as a starter have come from the fifth inning on, including all four Thursday.
Over their last nine games, eight of them losses, Cardinals starters have lasted only 32 1/3 innings, giving up 59 hits and 37 earned runs.
At 69-75, the Cardinals would have to go 12-6 the rest of the season just to get to .500 and 14-4 to have a realistic chance to win the division.
REDS 5, CARDINALS 4: The Cardinals, at least, were better situational hitters Thursday, although they suffered their seventh consecutive defeat. They had three sacrifice flies for their first three runs, and then Jim Edmonds singled home the tying run with nobody out in the ninth. But the next three hitters flied out, and the Cardinals completed an 0-7 swing through Arizona, Chicago and Cincinnati and dropped to 30-44 on the road.
NOTES AND QUOTES
--OF Rick Ankiel went 0-for-2 to wind up the seven-game trip 2-for-24. His average has dropped under .300 after it was .358 when the team left home.
--RHP Kip Wells was at 80 pitches after four innings, and when manager Tony La Russa was asked if he considered replacing Wells before the fateful fifth inning Thursday, he told a reporter, "Next time, call me on the dugout phone. ... My opinion was that he was good to go." Wells allowed five runs in the fifth.
--Wells is 2-10 in his career against Cincinnati. He has a chance to lead the NL in losses for the second time in three years. He was 8-18 with Pittsburgh in 2005.
--The Cardinals lost three games by one run and another by two runs in their seven-game slide. In the other three games, they were outscored 26-5.