Seattle's Kenji Johjima hits a grand slam against Kansas City. His four RBIs were the only runs allowed by Kansas City starter Brian Bannister in the Royals' 9-1 loss Saturday in Kansas City, Mo.

Kansas City, Mo. ? Ask Seattle’s Cha Seung Baek what was working well against Kansas City, and he reels off his entire repertoire.

But the Royals, who struck out seven times and managed only five hits off him, said the same thing.

While Baek (2-2) threw one of his best games of the year Saturday night, Kenji Johjima hit his first major league grand slam and Richie Sexson, after being kicked in the head, added a three-run shot in a 9-1 victory over the Royals.

Baek gave up five hits in seven-plus innings, throwing 74 strikes in his 98 pitches, with no walks. The only runner to get past second did so on an error.

“Slider, cutters were good today,” Baek said. “The changeup. Also the fastball.”

Mark Grudzielanek, one of two batters to get as far as second, said he seemed to throw everything well.

“He threw me everything,” Grudzielanek said. “He was coming in a little bit, mixing it up pretty good.”

As far as manager Mike Hargrove is concerned, the right-hander has become a part of the rotation.

“He threw the ball really, really well,” Hargrove said. “He was awfully good. He’s keeping the ball down, he’s changing speeds and he’s not leaving the ball in the middle of the plate. He’s really establishing himself as one of our guys.”

Brian Bannister (0-3) went seven innings and gave up four runs and eight hits, with two walks and no strikeouts. Raul Ibanez hit the first of his two doubles, Sexson walked and Ben Broussard reached on an infield single, loading the bases in the fourth.

Johjima, who had singled in the second to stretch his hitting streak to five games, lined the first pitch over the fence.

Sexson, knocked woozy by a knee to the head in a play at first base in the eighth inning, had a three-run shot in the five-run ninth off Ryan Braun.

Sexson fielded a hard grounder behind first hit by Tony Pena Jr. and tried to get to the bag on his knees to make the putout. Pena sprinted to first and was safe as he went tumbling over the bag and appeared to catch Sexson in the head.

The 6-foot-8, 235-pound Sexson, teased at getting whacked by the much smaller shortstop, said his calf and his head took the blow.

“It’s OK. I got a little lightheaded when he hit me,” he said. “I just got dizzy. It’s like playing football. You get your bell rung but you’re all right. It’s no big deal.”

Pena bunted safely in the third and went to second on third baseman Adrian Beltre’s bad throw. Then with two outs, shortstop Yuniesky Betancourt threw wildly to first on Grudzielanek’s grounder as Pena scored.

It was a rough night for Seattle center fielder Ichiro Suzuki, who still stretched his hitting streak to 19 games with an infield RBI single in his last at-bat in the ninth. Second baseman Grudzielanek reached out and made a backhand stop of the ball but failed to pick it up cleanly on what could have been scored an error.

But Suzuki also grounded into a double play for the first time this season and grabbed his right knee in apparent pain after crashing into the wall catching Mike Sweeney’s drive in the fourth.