Kansas City, Mo. ? Roger Clemens always will have a soft spot in his heart for Kansas City.

Clemens earned his 333rd victory with his 500th decision, dominating the Royals once again in leading the Houston Astros to a 7-0 victory Friday night.

“I love Kansas City. I love this ballpark,” said Clemens, who has won nine straight decisions against the Royals. “Here and Anaheim, I’ve enjoyed both cities very much.”

Clemens (5-3) allowed four hits in six innings, struck out six and walked three, lowering his major-league-leading earned-run average to 1.53. The Rocket, ninth on the careers wins list, has not surrendered a run in five road starts this year spanning 32 innings.

He improved to 24-7 with a 2.17 ERA against the Royals.

“I came out of the bullpen, I felt that my arm was a little bit heavy,” Clemens said. “My body felt fine, but my arm felt like it was dragging a little bit. I just had to get it going and trust my fastball.”

Kansas City pitcher J.P. Howell wipes his brow after allowing three runs in the first inning against Houston. The Astros beat the Royals, 7-0, Friday in Kansas City, Mo.

Clemens got three straight outs after Kansas City’s first two runners reached in the second. In the fifth, he walked Angel Berroa and David DeJesus with two outs, then threw a called third strike past Matt Stairs, who is 3-for-27 against the seven-time Cy Young Award winner.

“Our hitters did the job and made it easy for us – somewhat easy,” Clemens said. “It wasn’t a walk in the park because I was in trouble several times.”

J.P. Howell (1-1), who broke Clemens’ two-year strikeout record at the University of Texas before the Royals drafted him a a year ago, gave up four runs, five hits and three walks in six innings.

“I got a ton of phone calls pitching against J.P. tonight,” Clemens said. “To see him already in the big leagues, I tip my cap to that kid. He was in the running for an award this year at this time, and here he is in the major leagues. I’m very proud of him.”

The 22-year-old left-hander, coming off a victory over Arizona last week in his major-league debut, was a finalist last year for the Roger Clemens Award, given to the top college pitcher.

“I learned something tonight. I got away from what works best for me,” Howell said. “I didn’t use my weapons as much in the first inning as I did throughout the game. I learned tonight not to do that.”

Morgan Ensberg and Eric Bruntlett hit solo homers, and Adam Everett and Lance Berkman each had two RBIs for the Astros. Houston, coming off three straight losses at Baltimore, improved to just 8-26 on the road. The Astros have won 12 of 16 from the Royals in interleague play, including 11 of the last 12.

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Kansas City entered the night with five straight wins overall, its best streak in two years.

Howell looked every bit the nervous rookie in the first inning. Willy Tavares singled leading off, Berkman hit a long RBI double with two outs, and Houston loaded the bases when Ensberg walked and Jason Lane was hit by a slow breaking pitch.

Everett followed with a two-run double for a 3-0 lead before Howell retired Brad Ausmus on a grounder.

“If he gets a 3-0 lead, he’s going to bottle that up and love it,” Howell said of Clemens. “That’s why I didn’t give my team a chance. They were fighting uphill the whole game. That’s something I’ve got to take personal.”

Buddy Bell, who lost for just the fifth time in 16 games as Royals’ manager, did not think Clemens seemed not to have his best stuff.

“No doubt about that, he is able to go to another level when he really needs to,” Bell said. “His command is so good. He’s got great stuff, but he uses his head more. It was one of those nights where he was really, really good. We were hoping he wouldn’t be that good tonight, but he was.”