KANSAS CITY — The Royals’ post All-Star break success rolled along Thursday, as did the recent surge from their rotation.

This time it was right-hander Brad Keller, who endured the excessive heat at Kauffman Stadium to turn in a quality start — 6 1/3 innings, nine hits, four runs (two earned) and seven strikeouts.

Keller’s outing was the backbone of the Royals’ 6-5 victory over the White Sox on Thursday, completing a four-game sweep. Kansas City improved to 6-1 since the All-Star break, having won its first homestand of the season.

The heat index was well over 100 degrees.

“It was hot,” Keller said. “There was no hiding that. Everyone was in it, so that’s no excuse. You have to battle and hydrate between innings.”

Keller’s outing continued a nice run by Royals starters. Throwing out Brian Flynn’s emergency start Sunday when Homer Bailey was traded minutes before the game started, Kansas City’s starters have a 1.49 ERA over the past five games.

“We’re playing really good ball right now,” Keller said. “The offense is alive and killing it right now. The starters and relievers are doing their job. The break helped us, I think.”

Jorge Soler had the big blow on offense with a two-run opposite-field home run in a five-run third inning that wiped out a 3-0 deficit.

Keller got unlucky in the first as the White Sox cobbled together an infield hit, a bunt single, a passed ball and a fielding error to plate two runs.

But Keller held steady. And his biggest moment likely came after the Royals’ five-run third inning. Keller immediately struck out the side in the fourth, preserving Kansas City’s momentum.

“It was huge,” Keller said. “We took the lead, and to go out there and get a shutdown inning, especially with three strikeouts, it gave everyone confidence. We just kept it going.”

Royals manager Ned Yost was impressed with Keller’s shutdown inning as well.

“It was a big,” Yost said. “It’s just a statement. He was upset, I think, with himself a little bit with the situation in the first inning where they scored the two runs. He’s just telling his club when he goes out there in the fourth, ‘Hey, thanks for giving me the runs. I’m gonna hold up.’”

Another key moment came in the seventh when Keller left with one out and one on, ahead 6-4. Reliever Tim Hill came on and induced a 3-6-3 double play from AJ Reed to escape the frame. Reed’s grounder was just fair, and first baseman Cheslor Cuthbert snared it, threw a perfect strike to shortstop Humberto Arteaga and then hustled back to first to get the return throw.

“It was a good feeling [to get the double play],” Hill said “I saw it stay fair and then I was just like, ‘Get back to the bag! Get back to the bag! So everything was good.’”

As the Royals have charged out of the gate after the break, Hill is one of many players noticing a renewed spirit for a team determined to be more competitive during the final 10 weeks.

“The vibes in the clubhouse got a lot better,” HIll said. “It’s definitely a different energy, and it’s good.”