ST. PETERSBURG, Fla. -- Pinch hitter Ben Williamson delivered a walk-off single in the 12th inning as the Tampa Bay Rays staved off elimination with a 4-3 victory over the Milwaukee Brewers on Tuesday in Game 4 of the World Series.

The Brewers, who squandered a 12th-inning lead, still are up 3-1 in the best-of-seven series. Game 5 is set for Wednesday in St. Petersburg.

After rookie Cooper Pratt capped his four-hit performance with a homer to lead off the top of the 12th, giving Milwaukee a 3-2 lead, Tampa Bay saved its season with an epic rally in the bottom of the inning.

Junior Caminero reached on a throwing error by third baseman Joey Ortiz to open the 12th inning and chase Antonio Senzatela from the game.

Shane Drohan (0-1) relieved Senzatela and allowed a single to Liam Hicks to put runners on the corners. Jonny DeLuca's single up the middle plated pinch runner Cedric Mullins to forge a 3-3 tie.

Chandler Simpson's single loaded the bases before Williamson bounced a single into right field, knocking in pinch runner Nick Fortes to end the game.

Drohan permitted one run on four hits without retiring a batter.

Pratt, who also had an RBI double in the fourth inning, deposited a 2-2 sweeper from Ian Seymour (2-0) over the wall in left-center field in the top of the 12th. Seymour allowed one run on two hits in one inning.

Milwaukee's Jackson Chourio recorded two hits, boosting his total to 10 hits in the first four games of a World Series. The only other player to accomplish that feat was Babe Ruth in 1928.

The Brewers' David Hamilton atoned for an earlier miscue by homering to lead off the fifth inning, tying the game 2-2.

Simpson ripped an RBI double in the second inning and made a leaping catch at the wall in the ninth for the Rays, who (at least temporarily) prevented the Brewers from capturing their first World Series title.

In the second, DeLuca reached on a fielder's choice and hustled home on Simpson's double into the right field corner to open the scoring.

Sal Frelick reached on two-out single and scampered home on Pratt's double into the left field corner to forge a 1-1 tie in the fourth inning.

Tampa Bay answered in the bottom of the frame. Third baseman Hamilton's throw toward first base sailed off the mark, allowing Caminero to score from second and giving the Rays a 2-1 lead.

In the fifth, Hamilton sent a 0-2 fastball from Griffin Jax over the wall in right center field to forge a 2-2 tie. The blast chased Jax from the game.