Ryan O'Hearn and Whit Merrifield belted their first career grand slams Tuesday, and the Kansas City Royals bashed their way to a 12-2 win over the host Houston Astros at Minute Maid Park.

The Royals squared the three-game set with Houston by recording eight extra-base hits, six against Astros right-hander Collin McHugh (3-4) in three-plus innings.

O'Hearn capped a five-run third inning with his fourth home run of the season, lining a first-pitch cutter from McHugh 373 feet and into the seats in right field. O'Hearn followed a leadoff triple from Merrifield and a run-scoring double by Adalberto Mondesi during the third-inning slugfest. McHugh also issued a pair of walks in that frame as Kansas City extended to a 6-0 lead on the homer.

When Billy Hamilton (double) and Merrifield (RBI single) reached in succession to open the fourth, McHugh's night came to an end. Merrifield later scored when Hunter Dozier added a two-out triple off Astros reliever Chris Devenski.

McHugh, who also surrendered a solo home run to Royals designated hitter Jorge Soler with one out in the second, was charged with eight runs on seven hits and three walks with three strikeouts.

Merrifield smacked his grand slam off Astros left-hander Framber Valdez with two outs in the seventh and finished 4-for-5 with three runs and five RBIs. The home run was his sixth.

Mondesi and Soler also recorded multi-hit games for the Royals, who had lost four of their previous five games. It marked the first time since Aug. 13, 2004, that Kansas City recorded two grand slams in a game, when Abraham Nunez and John Buck did so against the Athletics in Oakland.

The run support proved gratuitous for Royals left-hander Danny Duffy (1-1), who produced his second consecutive solid start. After limiting the Tampa Bay Rays to one run on six hits and one walk over six innings in his second outing of the season on Thursday, Duffy carried a shutout into the sixth on Tuesday before surrendering a one-out solo home run to Alex Bregman.

Duffy was charged with a second run when George Springer greeted Royals reliever Glenn Sparkman with a first-pitch RBI single that scored Aledmys Diaz with two outs in the seventh. Duffy gave up six hits and three walks with five strikeouts over 6 2/3 innings.

After surrendering the run charged to Duffy, Sparkman tossed 2 1/3 scoreless innings.

--Field Level Media