"I'm absolutely shocked that a game of this magnitude could be decided like that," Boston starting pitcher Jake Peavy told reporters. "It just doesn't seem right."
The St. Louis Cardinals scored the decisive run on the obstruction call in the bottom of the ninth to beat the Boston Red Sox 5-4 and take a 2-1 lead in the best-of-seven series.
With one out, men on second and third, and the infield drawn in, second baseman Dustin Pedroia made a sprawling stop of a grounder and fired home for the first out.
Catcher Jarrod Saltalamacchia then threw to third to take out Allen Craig with a potential inning-ending double play.
However, the miscued toss got past third baseman Will Middlebrooks, who had lurched to his left to try and catch the throw. Left-fielder Daniel Nava backed up the play and threw home in time for Craig to be tagged out attempting to score.
The umpires decided that Middlebrooks had blocked Craig as he tried to leave third base, an obstruction call was ruled and the runner credited with scoring the winning tally.
During a post-game press conference, Boston manager John Farrell refuted suggestions that Middlebrooks may have lifted his legs to block Craig's passage to home plate.
"I can't say the legs were being raised in an effort to impede his progress. It's a tough way to have a game end," Farrell said.
"(Middlebrooks) is on the ground. If he tries to raise up, then he's clearly getting in the way for Craig to try to advance to home plate. But he got tangled up with him and that was the call," he said.
Middlebrooks said he handled the play the only way he could.
"When I went to push myself up, he was on my back pushing off of me, so what am I supposed to do there?" he asked.
He added that the umpire told him he had to "get of the way" in that situation.
The umpires later said intent was immaterial, that just being in the way constituted obstruction.
As he sat in the clubhouse after the game, a clearly annoyed Boston slugger David Ortiz said he had never seen any game end in such a fashion, let alone a pivotal World Series contest.
"I don't think you finish a World Series game like that," said Ortiz.
St. Louis will host Game Five on Sunday