It was Chapman's second blown save in as many outings, after surrendering a walk-off home run to the Indians' Asdrubal Cabrera last week in Cleveland.
"That was a tough one to lose. It was a tough one for Chapman, too," Reds manager Dusty Baker said. "It's a tough week and a tough week for Chapman. We're just glad this week is over and we'll start a new week tomorrow."
After going hitless in the first two games of the series, Votto sent a 1-0 pitch 387 feet to left for what the Reds thought plated the game-winning run.
Both sides' starters lasted eight innings in the pitchers' duel, before Chapman came on to close the deal for Cincinnati.
The hard-throwing lefty struck out the first batter he faced. Twins catcher Joe Mauer followed, and on the 10th pitch of his at-bat doubled off the left-field wall to bring Willingham to the plate.
Five pitches later, déjà vu set in for Chapman, as he watched Willingham round the bases following his two-run blast that landed in the upper deck of the left-field bleachers.
"I was waiting for something over the middle and hard and he threw it over the middle and hard," said Willingham, who was 2-for-4 on the day. "All I was trying to do was stay as short as possible. I wasn't trying to hit a home run. I was trying to stay short and I caught one just perfect and got it up in the air."
The Reds managed to put two runners on base in the bottom of the ninth, but former Reds reliever Jared Burton earned his first save of the season for the Twins.
In his eight innings of work, Reds starter Mike Leake allowed two runs on five hits and had thrown just 86 pitches entering the ninth.
But with Leake coming off a 114-pitch outing Tuesday, the most he's thrown all year, and working on just four days' rest, Baker decided a well-rested Chapman was the better call.
"That's Chapman's job," Baker said. "Did you know the hitters that were coming up against Leake that inning? Mauer, Willingham, Morneau, and that had been the fourth time he'd faced them. That's enough. He did his job. If I send Mike out and he gives it up, then it's 'How come you didn't send Chapman out?' You can't win unless you win the ballgame."
Leake said there was no lingering exhaustion from his last outing. He said he felt strong enough to finish the ninth, but still agreed with Baker's decision to go with Chapman.
"If they would have said, 'It's your inning,' then I would have gone out there," Leake said. "But you've got a guy throwing 100 [mph]. I thought it was a pretty good decision to put a fresh arm in there. It didn't work out."
Baker said Chapman's tendency to fall behind early in the count has been the source of his recent struggles.
The hard-throwing southpaw often turns to his 100-plus-mph fastball in those situations, and hitters are becoming more aware of it.
"He got behind in Cleveland, he got behind here, and guys know you're going to be coming with that fastball," Baker said. "When he missed with the 2-2 slider on Mauer [in the ninth], he knew what was coming -- fastball. If you get behind, bad things usually happen."
After not allowing an earned run in his first 24 appearances this season, Chapman has given up six earned runs in 5 1/3 innings of work since. In those six games, Chapman is 0-3 with two blown saves, and has an ERA of 10.13.
The Cuban closer acknowledged his recent issues, but said he feels it's something he can correct in the near future.
"At the beginning, everything was going well," Chapman said through a translator. "Right now, just the way that things happened, I'm going through a bad time right now and I believe that I will get out of this soon."
Baker never addressed the idea of possibly changing his closer.
"A week ago, we weren't even talking about this," Baker said. "Before, everybody was crying for Chapman, now they're crying for somebody else. That's the story when you blow a save. It's easy to say get somebody else, but where is somebody else better? This guy was the darling of baseball until this week. How soon everybody forgets."