Mauricio Dubon delivered a two-run single to cap a four-run eighth inning on Thursday as the Houston Astros rallied past the visiting Kansas City Royals 6-3 in the opener of a four-game series.

Dubon’s hit came after Zach Dezenzo drew a bases-loaded walk against John Schreiber that forced in the go-ahead run with two outs.

Houston had tied it at 3-3 when Lucas Erceg (2-5) threw wild to first base on Yainer Diaz’s one-out comebacker, which let Jose Altuve score from second.

Erceg was pulled after his miscue, while Kansas City first baseman Vinnie Pasquantino also exited after being clipped by Diaz on the play.

Ryan Pressly (1-3) pitched a scoreless eighth inning for the Astros, and Josh Hader notched his 29th save.

The Royals went up 3-2 in the seventh when Kyle Isbel hit a three-run double off of Houston reliever Bryan Abreu with two outs.

Kansas City rallied courtesy of ineffective defense by the left side of the Astros’ infield.

Third baseman Alex Bregman was ejected by plate umpire Alex Tosi in the fourth inning for arguing balls and strikes, and his absence defensively played a role in the Royals’ rally.

Rookie Shay Whitcomb replaced Bregman in the field, and while he wasn’t charged with an error in the seventh, his inability to cleanly handle a pair of chances set the table for Isbel.

After Salvador Perez reached with one out on a fielding error by shortstop Jeremy Pena, Paul DeJong beat out a potential inning-ending double play when Whitcomb was a tad slow with a throw to second that erased Perez.

Two batters later, Maikel Garcia reached on an infield single when Whitcomb mishandled a grounder before unleashing a late throw to first base.

Isbel followed by plating DeJong, Garcia and MJ Melendez, who had walked after DeJong reached.

His double closed the book on Astros starter Hunter Brown, who carried a shutout into the seventh and allowed two unearned runs on two hits and two walks with four strikeouts over 6 2/3 innings.

Houston went up 2-0 in the fifth on a two-run double from 35-year-old Jason Heyward, who signed with the Astros earlier Thursday.

Heyward’s knock came against Kansas City starter Brady Singer, who was charged with two runs on five hits and a walk while striking out six over six-plus innings.