Jonny DeLuca and pinch-hitter Ben Williamson singled home runs in a stunning 12th-inning rally as the Tampa Bay Rays staved off World Series elimination with a 4-3 win over the Milwaukee Brewers that forced Game 5.
Cooper Pratt hit a tiebreaking home run off Ian Seymour in the top of the 12th for his fourth hit of the game as Milwaukee neared a sweep and their first World Series title.
But the Rays, also seeking their first championship, rallied in the bottom half after a throwing error by third baseman Joey Ortiz on Junior Caminero's lead-off grounder against reliever Antonio Senzatela.
Liam Hicks singled off Shane Drohan, and DeLuca's single to centre drove in pinch-runner Cedric Mullins to tie the score at 3-3.
Chandler Simpson's single loaded the bases and Milwaukee employed a five-man infield with the infield in.
Williamson, who had been 1-for-15 in the post-season, hit a chopper over first baseman Jake Bauers and into right field.
"We've got a lot of fight in us. We're never going to shy away," Simpson said.
"We were going to keep fighting until the end - the last inning, the last out, the last play, the last pitch. We were going to keep fighting. That's what we did tonight."
Game 5 will be on Wednesday night (Thursday AEDT) at Tropicana Field.
Tampa Bay became just the fifth of 26 teams that fell behind 3-0 in the World Series to win Game 4. They will be looking to rewrite history, after the previous four lost Game 5.
Tampa Bay ended an eight-game winning streak by the Brewers, who were bidding to become only the second team to sweep a League Championship Series and the World Series.
David Hamilton homered for the Brewers, while Jackson Chourio had a single and double, improving to 10-for-20 in the series.
Pratt, a 22-year-old rookie whose go-ahead hit sparked the Brewers to a 5-4 win in Game 2, drove a slider into the left-field seats against Seymour. Pratt had tied the score at 1-1 with an RBI double in the second.
Simpson hit an RBI double off starter Dustin May in the second, but Milwaukee tied the score in the fourth against Griffin Jax when Sal Frelick hit a two-out single and came around on Pratt's double.
Caminero singled leading off the bottom half to chase May and advanced on a ground-out. DeLuca hit a hard grounder to Hamilton and Caminero twisted towards the grass to avoid the third baseman's tag, then came home when Hamilton bounced his throw past Bauers for an error.
Hamilton, Milwaukee's No.9 hitter, drove an 0-2 fastball at the letters from Jax into the right-field seats for his second home run of the post-season.