Kansas City, Mo. ? C.C. Sabathia is a big pitcher with a big problem.

“It hasn’t been a typical last three or four weeks for me,” Sabathia said. “I’ve just been bad.”

Sabathia (7-6) gave up a season-high seven runs on nine hits in only five innings in the Cleveland Indians’ 7-6 loss Sunday to the Kansas City Royals.

The 6-foot-7, 290-pound left-hander hasn’t won back-to-back decisions since June, when he was 5-3 and headed to his second straight All-Star game. He’s 2-3 with two no-decisions since.

“I have no excuses. I can’t put my finger on any one thing,” he said. “I just haven’t been pitching to my ability, and these are games we need to win. It’s kind of embarrassing.”

It’s also frustrating for Indians manager Eric Wedge, whose team is trying to position itself for a run at the postseason and needs all the help it can get from its No. 1 starter.

“He has to go out there, be aggressive, pick his spots and get ahead,” Wedge said. “That’s not what I’m seeing right now.”

The most humbling moments for Sabathia on Sunday came in the fourth inning.

First, he gave up an RBI single to Abraham Nunez, who just joined the Royals in a trade from Florida. Then, after giving up another single, Sabathia hung a slider to the Royals’ No. 9 hitter, John Buck.

Buck launched it into the left-field stands for a three-run homer and a 6-2 lead.

“I wouldn’t say I embarrassed him,” Buck said. “He’s embarrassed a lot more guys than I ever will. I was just trying to get good wood on it.”

Ken Harvey added a pair of one-run doubles for Kansas City, and Nunez had two RBIs in his Royals debut.

The Royals took two of three games for their first series win since they took three of four from Minnesota from July 15 to 18. That was also the last time, before this weekend, that they won back-to-back games.

“We’re finally getting back to playing the game the way it’s supposed to be played,” said manager Tony Pena, whose team had lost eight straight before winning its last two.

Darrell May (8-11) gave up two runs on six hits, walked two and struck out two in five innings.

Grady Sizemore and Travis Hafner homered for the Indians, who lost two straight for the first time since the Chicago White Sox won both ends of a two-game series July 21-22.

Sizemore’s two-run homer into the right-field stands in the sixth, and Hafner’s two-out solo shot in the seventh, both off reliever Scott Sullivan, got Cleveland within 7-5. Tim Laker followed Hafner’s homer with a single before Jaime Cerda relieved Sullivan and got Coco Crisp to ground out to third.

Cerda gave up an unearned run in the eighth, when Omar Vizquel’s sacrifice fly made it 7-6. That followed a fielding error by shortstop Angel Berroa on Ronnie Belliard’s one-out grounder.

Nunez answered in the eighth with an RBI double, giving the Royals an 8-6 lead.

“I’m very happy with what I did today,” said Nunez, who hit .173 in 58 games for the Marlins. “I just want a chance to prove that I can play everyday in the major leagues.”

Victor Martinez hit into a run-scoring double play in the ninth off Shawn Camp, who earned his second save in as many chances. Crisp then launched a fly ball into the gap in left-center for what looked to be a sure hit, but center fielder David DeJesus made a sliding catch to end the game.

“You wouldn’t have wanted to see my face if he hadn’t gotten to that,” Camp said.

Harvey’s first RBI double put the Royals up 1-0 in the first, and his second made it 7-2 in the sixth.

Cleveland went up 2-1 in the second on Crisp’s sacrifice fly and Ronnie Belliard’s RBI single, but the Royals tied it in the third on DeJesus’ one-run single.

Notes: Vizquel went 0-for-4, ending his season-high hitting streak at 13 games. … Nunez went 2-for-4 with a run. He started in right field to give Matt Stairs, who had seven RBIs in the series’ first two games, the day off. … Sabathia lost on the road for only the second time in six decisions, and his road ERA rose from 2.02 to 2.86 … Cleveland first baseman Lou Merloni, who left Friday night’s game with muscle tightness, returned Sunday and was 2-for-4. … Both of Sizemore’s homers have come against Kansas City. … The Royals scored 25 runs in the three-game series, a season high.