Ben Zobrist hit a go-ahead single in the seventh inning, reliever Wade Davis got replay help for a key pickoff in the ninth and the Kansas City Royals rallied from a three-run hole to beat the Houston Astros 5-4 on Friday, evening their AL Division Series at a game apiece.

The Royals knotted the game at 4 off Scott Kazmir and relievers Oliver Perez and Josh Fields in the sixth. Kansas City took the lead in the seventh when Alcides Escobar led off with a triple against Will Harris (0-1) and Zobrist followed with his single through the left side.

Kelvin Herrera (1-0) and Ryan Madson each tossed a scoreless inning of relief for the Royals, and Davis came on to close it.

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Davis walked Preston Tucker with one out, and speedy Carlos Gomez came in as a pinch runner. Davis snapped a throw that first baseman Eric Hosmer neatly snagged on one hop as Gomez made a dive back to the bag -- Gomez was initially ruled safe, but the call was overturned upon review. Jose Altuve then grounded out to end it, giving Davis a save.

It was a crucial victory considering what awaits Kansas City in Game 3 on Sunday: Astros ace Dallas Keuchel, who was 15-0 at home this season. Edinson Volquez will start for Kansas City.

Two starters acquired with October in mind, Johnny Cueto of the Royals and Kazmir of the Astros, pitched largely to a stalemate Friday, which meant the outcome hinged on the bullpens.

Kansas City's relief corps was simply better, allowing the reigning AL champions to become the first home team to win in six games this postseason.

Colby Rasmus homered, doubled and drove in two runs for the Astros, becoming the first player in major-league history with an extra-base hit in his first six playoff games. George Springer also drove in a pair of runs after hitting a solo shot in the series opener.

Salvador Perez homered for Kansas City. Hosmer also drove in a run.

The Astros jumped on Cueto right from the start, just as they did Yordano Ventura in the series opener. Rasmus doubled in a run in the first inning, and Springer added a two-run single in the second as restless Royals fans began to shower their ace with boos.

Perez got one back for Kansas City with a homer to left in the bottom half, but Rasmus matched him with his third home run in three games this postseason.

Cueto finally settled in, but it looked as if it would be too late. Kazmir allowed a run in the third, but otherwise had Kansas City off balance until the sixth inning.

Still trailing 4-2, Lorenzo Cain got the Royals' tying rally started with a double, and Astros manager A.J. Hinch called for Oliver Perez. He allowed back-to-back singles and a walk to leave the bases loaded for Fields, who walked Salvador Perez on four pitches to tie the game.

When the Royals took the lead the following inning, their shutdown bullpen made it stick.

CORREA HOBBLED

Astros rookie Carlos Correa fouled a pitched off the inside of his back knee in the fifth inning, and for a while appeared as if he might leave the game. He eventually remained in the game but struck out, though he did single off Herrera in the seventh.

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Keuchel threw six shutout innings in the Astros' wild-card win over the Yankees, and tossed eight shutout frames against the Royals in June. Volquez tossed two scoreless innings of relief in Kansas City's regular-season finale in Minnesota to tune up for the playoffs.