KANSAS CITY, Mo. -- The Kansas City Royals have been stumbling in September with a 9-13 record.

But behind the booming bat of Mike Moustakas, the Royals clinched the AL Central title Thursday night.

Moustakas homered, drove in three runs and reached five times as the Royals thrashed the Seattle Mariners 10-4 Thursday night.

With the Royals' victory and the Minnesota Twins' loss to the Cleveland Indians, Kansas City wrapped up the American League Central championship.

"It seemed like it took forever, but we continued to battle," said Lorenzo Cain, who had a two-run single in the sixth to put the Royals ahead for good. "We got down early, but guys stepped up in clutch situations."

The Royals have not won a division crown since 1985 when they were in the AL West. The Royals hold a two-game lead over Toronto for the best American League record and homefield advantage.

"We've got to continue to fight," Cain said. "We can't pack it in yet. We'd love to play in front of our home crowd. It's definitely a great feeling to play in front of these guys. They've been supporting us all year long, so we definitely want to win home-field advantage."

Right-hander Johnny Cueto (3-6) picked up the victory, holding the Mariners to three runs and seven hits over seven innings, his second straight quality start. He had lost his previous five decisions.

"Hopefully this is just the start of it and we can keep it going," Royals left fielder Alex Gordon said. "It feels great. We expected to win. We believed in ourselves. At the end of the day that's all that matters."

Logan Kensing (1-1), the fifth of seven Mariners' pitchers, took the loss.

Right fielder Alex Rios also had three hits for the Royals, including a run-producing triple in a three-run eighth.

Mariners first baseman Logan Morrison homered to lead off the ninth, but the party erupted on the field minutes later as the crowd of 34,244 remained standing and cheering as players celebrated on the field.

The Royals seized an early 2-1 advantage, but muffed opportunities to enlarge their lead.

Second baseman Ben Zobrist doubled down the left-field line with one out in the first. When Mariners catcher Jesus Sucre attempted to pick Zobrist off, he airmailed the throw into right-center, allowing Zobrist to score.

Third baseman Mike Moustakas homered to lead off the Royals second. It was Moustakas' 21st home run and 74th RBI, both career highs. Moustakas had 20 home runs and 73 RBIs in 2012.

The Royals loaded the bases after that with singles by catcher Salvador Perez, shortstop Alcides Escobar and left fielder Alex Gordon, but left them that way. Zobrist flied out to shallow right on a 3-1 pitch and center fielder Lorenzo Cain rolled one to short.

Mariners left-hander James Paxton left in the second with a broken fingernail after giving up the single to Escobar. J.C. Ramirez replaced Paxton, who was led off the mound by the trainer.

"I'm frustrated," Paxton said. "It's hard. I want to be out there pitching and stuff like this keeps on happening. I just have to keep on going, come out the other side and just deal with it."

The Royals again loaded the bases briefly in the third. Designated hitter Kendrys Morales and Moustakas drew walks and right fielder Alex Rios singled. Morales, however, circled third base too far and was out trying to get back.

The Mariners scored a run in second when center fielder Brad Miller's two-out double to left got right fielder Mark Trumbo home from first.

The Mariners moved in front with a two-run fourth, which second baseman Robinson Cano led off with a single. He stopped at third on Seth Smith's double. Trumbo's double down the right-field line scored both off right-hander Johnny Cueto.

"We couldn't cash in early," Mariners manager Lloyd McClendon said. "We certainly had some opportunities. And so did they. It's just one of those games. They broke it open."

The Royals tied it at 3 in the bottom of the fifth when Hosmer greeted left-handed reliever Rob Rasmussen with a homer to center on his third pitch.

NOTES: Royals RHP Greg Holland has a right elbow torn ligament with surgery likely. He will see Dr. Neal ElAttrache next week in Los Angeles for a second opinion. Manager Ned Yost called it a "significant tear" and rest would not help. ... The Mariners have opted to shutdown RHP Taijuan Walker for the remainder of the season. Walker, who was on the disabled list for nearly 10 weeks last year, has thrown 169 2/3 innings. "To run him out there at this juncture of the season, to me, is not a win-win for nobody involved, so the best thing to do is to make sure that he's healthy going into next season," Mariners manager Lloyd McClendon said. ... Royals C Salvador Perez was back in the lineup after leaving in the eighth inning Wednesday with a sore knee. ... Mariners LHP Vidal Nuno will start the series opener Friday against the Angels. ... Indians LHP Carlos Carrasco and Royals RHP Edinson Volquez are the Friday probables.