The first two innings against the Minnesota Twins changed all that.
Ka'aihue hit two home runs and drove in a career-high four runs to lead Kansas City to a 10-1 victory over the Twins on Tuesday night.
"That's what he is capable of doing," Royals manager Ned Yost said. "When he steps into that box he's going to make opposing pitchers a bit nervous."
The Twins have dropped a season-high five straight since clinching the AL Central title on Sept. 21.
"I don't think there's a whole lot of panic in here," Twins starter Nick Blackburn said. "I think we'll be fine. This team's a pretty good, calm group. I'm really not concerned about what happened tonight. I'm not happy about it, but I'm really not concerned about it. As long as I'm sharp next outing and take some confidence into it I'll be fine."
Ka'aihue hit a three-run homer in the first off Blackburn (10-11) and then led off the second with his seventh home run of the season. It was his first career multihomer game.
He almost had a third one in the seventh, sending a drive off the right-field bullpen fence for his first big league triple.
"It was a crazy night," Ka'aihue said. "It was just one of those nights, a real good night. I think when I first got here, I was trying to do things I wasn't capable of doing. Now I'm just trying to play my style of baseball. Ned had been talking to me about it and encouraging me. Hopefully, this continues."
Sean O'Sullivan (4-6) held the Twins to one run on five hits and six walks in six-plus innings.
Blackburn gave up eight runs on eight hits and two walks in 4 1/3 innings. He also balked home Mike Aviles, who led off the fifth with a triple for his third hit.
"I couldn't execute my pitches and locate," Blackburn said. "It was the worst I've had in a long time. I came in and watched some film and the mechanics were pretty good. I was missing spots and just wasn't getting my pitches where I wanted them to."
He singled and doubled before that, so in his final at-bat in the sixth, he was swinging for a home run to complete the cycle.
"Of course. Why not, right?" Aviles said. "We're up a bunch of runs, might as well try. [Glen] Perkins threw me some nasty pitches. I didn't do a good job of being selective. That was one time when I was just trying to hit a homer and that was probably the reason I popped up to short."
The Twins have allowed 46 runs in the five-game skid, the most in any five-game stretch since they gave up 52 June 14-18, 2003.
"It's kind of a return to the same story from last night," Twins manager Ron Gardenhire said. "We didn't pitch well. These guys are swinging the bats well. We're getting beaten around. They're having fun at our expense. It's not much fun for us. We have to weather the storm."
Ka'aihue also scored four runs, matching David DeJesus for the Royals' season high. ... Kansas City beat the Twins 10-8 on Monday night, giving the Royals a double-digit total in back-to-back games for the first time since Sept. 8-9, 2006 at Boston. ... Twins DH Jim Thome returned to Minnesota to receive treatment on his back. ... Royals outfielder Mitch Maier (sore left knee) and infielder Wilson Betemit (bruised shin) missed their third straight games. ... Royals rookie right-handed reliever Blake Wood retired all six batters he faced, striking out the final four.