Michael Massey homered to ignite a four-run second inning in support of right-hander Michael Wacha, who carried a shutout into the seventh inning of the Kansas City Royals’ 7-5 win over the host Houston Astros on Monday.The Royals, 17-4 over their past 21 games, maintained their torrid pace when five consecutive batters reached in a three-run third, establishing a 7-0 lead. Jonathan India led Kansas City with three hits, while Bobby Witt Jr., Vinnie Pasquantino and Kyle Isbel had two hits apiece.Jeremy Pena, Jose Altuve, Yainer Diaz and Jake Meyers each collected two hits for the Astros, who had won three of their previous four games.Massey clubbed his second home run of the season leading off the top of the second to open the scoring. Astros right-hander Ryan Gusto (3-2), who stranded two runners in the first inning, seemed to find his stride by retiring Cavan Biggio and Drew Waters following the Massey home run. He did not.Isbel smoked a two-out double to right field, and India followed with an RBI single. Witt, who scorched the ball in his first three plate appearances, followed with a run-scoring triple to right-center. Pasquantino drove home Witt for a 4-0 lead.The Royals didn’t wait until there were two outs in the third to exact additional damage. Gusto issued one-out walks to Massey and Biggio before Waters extended the lead to 5-0 with a single to left.