KANSAS CITY — For the second time this week, the Royals held a late lead, which in recent years almost assured them a victory.

But those bullpens of yesteryear are but a memory now. The Royals gave up a one-run lead in the ninth inning to start this homestand on Monday in an eventual loss, and the bullpen couldn’t hold a one-run lead against the Astros on Sunday afternoon.

Right-hander Brandon Maurer gave up a game-tying home run to Carlos Correa in the eighth inning, and the Astros added two more runs in the inning off Maurer and left-hander Tim Hill for a 7-4 win and a sweep of the three-game set at Kauffman Stadium. The Royals have lost six straight, and 12 of 13.

Royals 22-year-old starter Brad Keller was solid against a red-hot Astros team that has won 11 straight. Keller gave up three runs over six innings in his fourth Major League start.

“He’s a kid with a lot of aptitude,” manager Ned Yost beamed afterward. “He learns very quickly. He retains, he seeks knowledge. He’s a smart kid.”

Even the Astros were impressed.

“He’s 22? Really? Wow,” Correa said. “A lot of potential. A really good pitcher. He’s not a comfortable at-bat out there. He did a good job shutting us down. Wow, he’s 22? That’s impressive. He’s a good pitcher.”

Hunter Dozier clubbed his third home run of the season, a two-run shot in the third inning that gave the Royals a 4-2 lead.

Keller got out of a huge jam in the sixth. Clinging to a 4-3 lead, Keller gave up singles to Josh Reddick and Evan Gattis that put runners on first and third with none out.

But Keller struck out Marwin Gonzalez on a 3-2 fastball, then he got Brian McCann to roll into a 4-6-3 double play, preserving the lead.

“I was able to get deep into the game, keep the team in it,” Keller said. “To keep a team like that, keep the ball on the ground with them, I feel like I did pretty well as far as that. That’s a good hitting team, and they’ve got pop so to keep them on the ground, I’m happy with that.

“[In the sixth we had a] leadoff single and then wild pitch, then another hit, just kind of snowballed real fast on me. I just kind of settled down. Then I got a three-ball count to Gonzalez right there, and settled down and made pitches right there. I’m pretty happy with that as well.”

Royals super utility man Whit Merrifield fouled a pitch off the inside of his left knee and immediately went to the ground in the second inning. He eventually limped off the field with help from athletic trainer Nick Kenney and was replaced by Adalberto Mondesi. The club announced that Merrifield sustained a contusion and is considered day to day.