KANSAS CITY, Mo. (AP) -- Robinson Cano wasn't focused on the distance. He was just happy to see the ball clear the fence.
Cano homered twice and drove in four runs and Hisashi Iwakuma struck out a season-high 10 as the Seattle Mariners romped past the slumping Kansas City Royals, 11-2 Tuesday night.
The Mariners muscled out five home runs, with Cano's 433-foot three-run shot in the seven-run third his longest in more than two years.
"I knew it was a good swing but I didn't think it was going to be that far," Cano said. "But for me it doesn't matter how far it goes if it goes over the wall."
Kauffman Stadium is not a friendly park for power hitters, but it was not too big for the Mariners.
"It doesn't usually play this small," Mariners manager Lloyd McClendon said. " I thought the ball jumped, really jumped in early BP tonight and I think it carried over into the game."
The AL Central-leading Royals have dropped 12 of 17. Their magic number for clinching the division remained three.
Cano and Kyle Seager each hit solo homers in the first inning for Seattle, which has the league's best record in September at 13-6 but is still three games under .500 (74-77). It was Seager's 25th home run and his seventh in 23 games.
Brad Miller and Jesus Montero also connected for Seattle.
Cano hit a three-run shot in a seven-run third inning for his 15th career multihomer game. Cano's next hit will be the 2,000th of his career.
Iwakuma (9-4), who is 7-2 in his past nine starts, curbed the Royals on three singles over seven scoreless innings. He has allowed one run and 10 hits in 13 innings in his past two starts, while striking out 19 and walking one.
Royals starter Jeremy Guthrie (8-8) was pulled after Miller homered with one out in the third. Guthrie retired only seven of the 17 batters he faced, allowing nine runs on nine hits, four home runs.
"When he missed location, they didn't miss it," Royals manager Ned Yost said.
Guthrie is 1-3 with an 8.07 ERA in seven starts since the All-Star break, allowing 58 hits, including 12 home runs, and walking 11 in 35 2-3 innings.
Yost said he would "sleep on it" when asked if Guthrie would make another start.
Montero hit a two-run shot in the fourth off rookie right-hander Miguel Almonte for the final Seattle runs.
Alcides Escobar had three of the Royals' hits, scored a run and drove in a run. Alex Rios doubled in the ninth to extend his hitting streak to 11 games.
Mariners: RHP Felix Hernandez, who exited in the sixth inning Sunday with elbow tightness, played catch Tuesday and said he would not miss a start.
Royals: RHP Greg Holland, with lingering elbow issues, was replaced by RHP Wade Davis as the closer. ... 2B Omar Infante has a left oblique strain and is probably out two to four weeks. ... SS Alcides Escobar returned after missing the previous two games with a bruised left elbow after being hit by a pitch Friday.
Mariners 1B Logan Morrison was absent to be with his wife, who gave birth to the couple's first daughter, Sophia. Montero replaced Morrison in the lineup and went 2 for 5 with a home run. He is hitting .500, 12 for 24, in six games at Kauffman Stadium.
Mariners: LHP Roenis Elias is 1-1 with a 6.46 ERA in three career starts against Royals.
Royals: RHP Yordano Ventura has won eight of his past nine decisions.