With the Twins holding a 3-0 lead in the top of the ninth, Royals first baseman Mark Teahen came up to the plate to face closer Joe Nathan as the tying run for Kansas City.
Nathan had just entered the game with one out and runners on first and second -- both had reached base off starter Nick Blackburn.
On the first pitch Nathan threw, Teahen flipped a fly ball down the left-field line. A hit that appeared to be a bloop single -- if it fell in -- turned into a game-tying, inside-the-park home run.
All due to what Gardenhire deemed to be a mistake by his left fielder, Delmon Young.
Knowing the situation with the tying run at the plate, the Twins outfield was playing deep to prevent doubles. But rather than remaining on his feet to field Teahen's hit, Young tried to make a sliding grab along the foul line.
The ball landed in front of Young's glove, bouncing back toward the left-field wall. Young appeared to take a moment to look back at the umpire who had called the ball fair before heading to retrieve it.
And, in the span of a few seconds, what had appeared to be a sure victory for the Twins suddenly turned sour.
"You can't leave your feet in left field in that situation," Gardenhire said. "You have a three-run lead in the ninth, and I know it was right on the line. That's not one of those plays when you can go diving all-out and let three runs come in there. ... It was an honest effort mistake. He was trying to make a play. But we have to know situations, and we kind of let that one get away."
After the game, Young admitted that he made a mistake. He thought he had crossed the foul line when he began his slide and was just trying to get an out.
"But in that situation, you should just play it on the hop and throw it back in with your closer on the mound," Young said.
As the entire Twins' dugout stared out at Young, the first two runners scored and Teahen sprinted around the bases. By the time Young was prepared to make his throw, Teahen had rounded third.
"You know he's going to be running," Young said. "He has good speed. When I looked up, he was already halfway to third."
Teahen's inside-the-park home run was the first for the Royals since Mark Grudzielanek hit one on Aug. 20, 2006, vs. Oakland.
"I guess I placed it right. Just putting Nathan in play is a tough at-bat," said Teahen, who was 0-for-7 against Nathan previously.
"I hit a couple of balls like that against St. Louis here last year, so I thought I had a shot at it. Run hard out of the box and see what happens."
It marked the first blown save of the season for Nathan, who was 13-for-13 in save opportunities coming into Tuesday's contest. But while Nathan appeared to be as agitated as anyone by the play, he recovered to record the final two outs of the ninth.
"You just pitch, that's all you've got to do," said Nathan. "I've always said there are times you are going to go out there and make good pitches and the results won't be in your favor. I felt good out there. I felt like I was making pitches. It was just a first-pitch, lazy fly ball that he just happened to put it in a good spot."
Teahen's homer also ruined Blackburn's chance for a victory on what had been his best performance of the year.
Blackburn cruised through the majority of his outing. He held the Royals scoreless through eight innings and scattered just eight hits on the night. He had no problems finding the plate, throwing 75 of his 92 pitches for strikes.
"I finally felt sharp up on the mound," Blackburn said. "Everything felt like it was coming out of my hand well tonight. It doesn't really matter about being a factor in the decision. I kept my team in it, and that's basically all a starter is asked to do. Overall, we won and that's most important right now."
The team's 12th-inning comeback did help take some of the sting out of the events in the ninth inning. The rally began after Joe Mauer drew a one-out walk against Royals right-hander Leo Nunez.
The Royals then had their own blunder in left field as Jose Guillen missed a ball hit there by Justin Morneau. The miscue by Guillen allowed Mauer to advance to third on Morneau's single. And when Guillen threw to third in an attempt to nab Mauer, Morneau advanced to second.
The play set up the winning run. Michael Cuddyer came up with the big hit, a single to right that scored Mauer from third and put the Twins in line for the victory.
But while it will show up as an important mark in the left-hand column for Minnesota, it was a win that left most of the Twins clubhouse looking somber rather than jubilant.
"I'm having a hard time with this one because I'm just so disappointed," Gardenhire said. "We won the ballgame and kept playing, but it sure was disappointing there in the ninth. ... It was really disappointing to not see it end there, because we had pitched so well up to that point."