St Louis Cardinals moved to within one victory of their first World Series title in 24 years with a dramatic 5-4 comeback win over the Detroit Tigers.
David Eckstein's hit proved crucial
David Eckstein drove in Aaron Miles for the game-winning run in the bottom of the eighth after St Louis had battled back from 3-0 down at Busch Stadium.
The Cardinals now lead 3-1 lead in the best-of-seven Fall Classic.
They can claim their first World Series win since 1982 with victory in game five on Friday before their home fans.
A Tigers victory would send the Series back to Detroit for game six, which is scheduled for Saturday.
Game four was delayed by 24 hours after torrential rain washed out play on Wednesday.
Are we in a good position? Absolutely not
Tigers manager Jim Leyland
Detroit took a 3-0 lead with a solo home run by Sean Casey in the second inning and a two-run burst on run-scoring singles by Casey and Ivan Rodriguez in the third.
The Cardinals hit back with runs in the bottom of the third and the fourth, and took advantage of two slips by the Tigers in the seventh to score twice and seize a 4-3 lead.
The visitors did level the match at the top of the eighth but Miles' run sealed victory.
"We know how good the Tigers are," said St Louis boss Tony La Russa.
"We have to come out tomorrow and play as good as we can, hard as we can, and see what happens."
Tigers manager Jim Leyland is refusing to concede defeat but admits his side have a lot of work to do.
"We have to win three games in a row," he said. "Can we do that? Absolutely. Are we in a good position? Absolutely not."