Isaac Paredes socked a walk-off home run leading off the ninth inning and the Houston Astros took a 2-1 win over the visiting Kansas City Royals on Tuesday to knot the three-game series.Paredes produced his first career walk-off homer against the third pitcher of the game for the Royals, John Schreiber (1-2). The Houston third baseman belted a 0-1 sweeper 375 feet and out to left-center field for his fifth home run of the season.Astros reliever Bryan Abreu (1-1) pitched a perfect top of the ninth.Left-handed starters Kris Bubic and Framber Valdez engaged in a riveting pitchers’ duel.Bubic tied his career high with nine strikeouts over 6 1/3 innings. He yielded a run on six hits and one walk.Valdez worked a season-high-tying eight innings, allowing one run on six hits and one walk with seven strikeouts.Kansas City’s Jonathan India and Canha produced singles in the fourth, but Valdez averted damage by inducing Salvador Perez to ground into an inning-ending double play.