Kansas City, Mo. ? Zack Greinke is developing into a strikeout pitcher at age 24.

The right-hander matched a career high with 10 strikeouts and Alex Gordon hit a two-run homer as the surging Kansas City Royals beat the Colorado Rockies, 7-3, Tuesday night.

“When there are runners on base, that’s the only time I really try to strike anybody out, at least from the first pitch,” Greinke said. “I threw a lot of quality pitches and got ahead in the count and they chased them. A lot of strikeouts weren’t strikes.”

The Royals have won four straight and nine of 10, all against National League clubs. Their 11-3 record is the best in interleague play.

The game included a frightening moment in the bottom of the second inning when plate umpire Brian O’Nora was hit in the head by a shattered piece of Miguel Olivo’s broken maple bat.

With blood streaming down his face, O’Nora rushed to Kansas City’s dugout, where Jose Guillen quickly covered the umpire’s head with a towel.

O’Nora came out of the game and was treated by Kansas City trainer Nick Swartz. The Royals later announced that O’Nora had a small cut on his forehead and was taken to St. Luke’s Hospital for further evaluation.

Earlier in the day, Major League Baseball said it will start testing bats following Tuesday’s meeting of a player-management safety committee, but the sport made no decision on the contentious issue of banning maple models.

“They are very, very dangerous. I’m surprised that this is the first incident we’ve seen,” Royals manager Trey Hillman said. “It could have been worse, a lot worse. It looked a lot worse than it was. My understanding is that he is OK.”

After O’Nora was hurt, both teams left the field and the game was delayed for 13 minutes before resuming with three umpires.