The Washington Nationals forced a seventh-game World Series decider by beating the Houston Astros 7-2 in game six to square the series at 3-3.
It is the first time in World Series history that the visiting team has won each of the first six games.
Nationals starter Stephen Strasburg pitched into the ninth inning, not giving up a run after the first.
Meanwhile, Houston-born third baseman Anthony Rendon excelled against his home town side, driving in five runs.
The winner-takes-all game seven will be held at Houston's Minute Maid Park on Wednesday at 20:08 ET (Thursday, 00:08 GMT).
In a major boost for the Nationals, star pitcher Max Scherzer will be available to start that game after having a cortisone injection to alleviate the neck and back spasms which caused him to miss his scheduled start on Sunday.
Having lost three successive games in the US capital to put them on the brink of losing the series, the Nationals took an early lead when Rendon drove in Trea Turner, only for Houston to hit back when Jose Altuve scored George Springer on a sacrifice fly before Alex Bregman's home run made it 2-1.
But Adam Eaton and Juan Soto's solo homers, the latter a towering blast into the second tier of seats in right field, made it 3-2 and meant Astros starting pitcher Justin Verlander left after five innings.
There was controversy in the seventh inning when Turner was adjudged to have run outside the base paths and impeded fielder Yuli Gurriel at first base.
He was given out by the umpires, enraging Washington manager Dave Martinez, but the umpire's call was upheld after a lengthy check with the replay command centre in New York.
The Nationals channelled their frustration in the best possible way as Rendon's home run off reliever Will Harris made it 5-2 - although Martinez continued his tirade at the umpires after the inning was over, having to be physically restrained by two of his coaches, and was ejected from the game.
Rendon drove in two more runs in the top of the ninth to maintain the Nationals' dreams of a title on their 'Fall Classic' debut.
It was two years to the day since the Astros beat the Los Angeles Dodgers 13-12 in an enthralling game five on the way to their first World Series title, but there was to be no fairytale comeback this time for the hosts, who will send Zack Greinke to the mound in game seven.
Seth Bennett, BBC World News in Houston
This has not been a crash-bang-wallop World Series, which has swung one way and then the other during each game, but instead a more sedate page turner that keeps threatening a dramatic ending.
North American sport has never seen a seven game series where the first six were all won by the away team. It defies all explanation and logic. From the experts to the players and fans nobody can quite explain why the away teams have had so much success.
Washington looked down and out, but got a throwback pitching performance from Stephen Strasburg - once a frightening talent, now a confirmed superstar - who dominated game six. He was supported by his team-mates, Anthony Rendon throwing his hat into the MVP ring, knocking in five runs, including one towering home run, clutch hitting just when his side needed it.
Game seven will bring together two terrific pitchers in Max Scherzer for Washington and Zack Greinke for Houston.
Scherzer has recovered from a neck and back injury, which kept him out of game five. After the marathon of the 162 game regular season it all comes down to one game to see who will be crowned World Series champions.
Houston remain slight favourites to win a second title in three years, but if this series has shown anything, it is better not to predict, just sit back, relax and enjoy two very good baseball teams giving it everything they have got to become champions.