Through the first seven innings, Bard had been tremendous, save for a fluky three-run second, when he committed two balks and a wild pitch.
But Bard started the eighth by walking leadoff man Jarrod Dyson and then the second batter, Alex Gordon.
Up to 96 pitches and seemingly losing some command, Bard's night was over.
Three pitches later, the night went up in flame for Bard and the Red Sox.
Matt Albers, who had thrown 9 2/3 shutout innings in his previous seven outings, served up a three-run homer to Billy Butler. Gone was the lead. Gone was the win the Red Sox thought they had.
"I'm trying to go down and away right there, which I still think is the right pitch," Albers said. "I talked to [catcher Kelly Shoppach] about it, and I could sit here and second guess, but I didn't execute. I didn't stay back on the rubber quite enough and the ball leaked over the plate. And he's a good hitter."
Butler went from goat to hero in the course of 24 hours.
"Obviously if I hit it on the ground to somebody, they're going to get a double play. There's no secret there," Butler said. "That's just the way things work out. Last night, I hit into a double play, tonight I get the big hit."
Even though Butler's blast will wind up being the signature highlight of this game, Bard feels responsible for the loss, which put him at 2-4 on the season with a 4.83 ERA.
"I felt great. I felt strong," said Bard. "You get to 90 pitches, I'm not tired to the point where I need to come out of the game by any means. But there is a fatigue that sets in, and it's about learning how to pitch with that little bit of fatigue. It's not my arm; my arm felt great. It's your whole body -- your legs, your lower back, everything."
In other words, Bard is still adjusting to his new role.
"Just learn how to pitch in those conditions," said Bard. "That's kind of where I'm at right now -- trying to learn how to finish games and get through that 100-110 pitches strong all the way through the end instead of tailing off and losing command late."
After the fact, Bard could see where it went wrong.
"I was just trying to do too much," Bard said. "I smelled the finish line and wanted to get that win for our team really bad. I was just trying to do too much with those pitches and maybe didn't trust them to the middle of the zone like maybe I had been."
Shoppach wonders if the speed of Dyson might have led to the walk of Gordon.
"There was a lot going on when that little guy gets on base. You get distracted," Shoppach said. "You're approaching that part of the game where you start to get your bullpen involved. He was still throwing the ball well. I thought we maybe lost a little focus towards the plate. That happens, especially when those quick guys get out there. They just cause havoc."
It was a game the Sox had led since the fifth, when a gift by the Royals -- Chris Getz threw a double-play ball away -- had put Boston up, 4-3.
The Royals nearly came back in the seventh. The inning started with Jeff Francoeur and Mike Moustakas striking singles. Getz dropped down a bunt, putting runners at second and third with one out.
Bard then got a major assist from his defense. Alcides Escobar attempted a safety squeeze, but first baseman Adrian Gonzalez swiftly fielded it and fired home to Shoppach.
Francoeur probably would have scored if not for a textbook block of the plate by Shoppach, who tagged the runner out.
"I think that play, more than anything, was all Shoppach," said Gonzalez. "I did the best I could with it, but that play was all Shop."
The escape was complete when Bard struck out pinch-hitter Brayan Pena, but there was no such luck in the eighth, handing the 12-17 Red Sox their sixth loss in the last seven games.
"You never want to be too surprised, but I thought [Bard] was in complete control of the game," said manager Bobby Valentine. "After his second inning, when he kind of gave away three runs, he was in complete control of that game with all his pitches. I was very surprised to see him walk those hitters. I had Matt ready in case something happened. Something happened."
The Red Sox jumped out first, as Will Middlebrooks continued his torrid hitting with a one-out double to right in the second. With that hit, Middlebrooks joined Enos Slaughter (1938) as the only players in modern history to get five extra-base hits in his first five Major League games. More importantly for the Red Sox, it sparked a rally. Marlon Byrd singled to right and Middlebrooks scored on an RBI single by Shoppach.
Later in the inning, Dustin Pedroia walked with the bases loaded, and the Red Sox had a 2-0 lead. But they also had an injury, as Middlebrooks (left hamstring tightness) left in the bottom of the second and was replaced at third base by Nick Punto.
Middlebrooks is hopeful he can return to the lineup Wednesday.
The Royals got to Bard in that bottom of the second inning. With runners on second and third with one out, Bard balked in a run. Later in the at-bat, with Getz still hitting, Bard balked a runner to third. Getz then produced an RBI single to tie it at 2. Bard uncorked a wild pitch, allowing Getz to move to second. And after a fielder's-choice grounder moved Getz to third, Humberto Quintero scored him with a single, giving Kansas City a 3-2 lead.
It was the first time a Boston pitcher had two balks in one inning since John Dopson on June 13, 1989, against the Tigers.
"Just chalked it up to being just a fluke thing," said Bard. "It [stinks] that they got three runs out of it. They probably get one or two there either way, even without them. I just tried to settle back in there. I knew I was making good pitches, and I wasn't going to let that take me out of my game completely."
Kansas City's 3-2 edge held until the top of the fourth, when Boston rallied. Mike Aviles ripped a two-out double to left and Pedroia brought him home with a single.
But there were more ups and downs to come. Unfortunately for the Red Sox, they had more of the latter, adding up to yet another difficult defeat.