SEATTLE -- Danny Duffy threw six-plus strong innings and left just one pitch up. It proved to be one too many.
Seattle got to the Kansas City left-hander for a run in the third inning and that was all the Mariners needed in a tidy 1-0 victory over the Royals on Thursday night.
Duffy allowed just two hits, but one was a leadoff double in the third by Mike Zunino, who would score the winning run.
"If I could get one pitch back it probably would have been the double, obviously," Duffy said. "I left it up, it was a two-seam. He went out and got it and put a good swing on it, not much you can do."
Duffy nearly escaped trouble after recording two outs, but after intentionally walking Robinson Cano, Corey Hart singled to score Zunino with the game's only run.
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"Cano's hitting .340 over his last 16 games, he's got five game-winning RBI," Royals manager Ned Yost said. "He's one of the top hitters in the American League ... you take your chance with Corey Hart, even though he is a good hitter, too."
It was the second time in as many starts that Duffy allowed two hits and a run after pitching out of the bullpen to begin the season.
Kansas City was unable to get anything going offensively against Seattle starter Hisashi Iwakuma. The All-Star scattered four hits over eight innings, while striking out seven and walking none. The Royals reached second base just once against him.
Iwakuma (2-0) was making his second start after beginning the season on the disabled list with a strained tendon on the middle finger of his pitching hand.
"He's getting better each and every time out," Mariners manager Lloyd McClendon said. "I think if you asked him, there's a lot more in there. There's a lot of room for improvement, but that just goes to show how good he really is."
The right-hander has thrown 48 2/3 consecutive scoreless innings against AL Central teams, the second-longest streak by any pitcher against one division dating to 1974. Orel Hershiser tossed 55 straight scoreless innings against NL West opponents in 1988.
Kansas City showed signs of life in the ninth when it earned two walks off Fernando Rodney, but the Royals were unable to cash in and the Mariners closer earned his 10th save in 11 chances.
The victory makes Seattle winners for the 11th time in 14 games since losing eight straight from April 15-22. The shutout gives the Mariners 27 straight innings without allowing a run to the Royals, a streak dating to September 2013.
"Our guys are grinders," McClendon said. "I think they've proven that they know how to get back up off the mat, so to speak. This has been a tough month and a half for us in a lot of different ways, but I think when it's all said and done, maybe we're not as bad as people thought we were going to be."
NOTES: Seattle LHP James Paxton, on the DL with a strained left lat muscle, played catch and is scheduled to throw a bullpen session Friday. ... Mariners RHP Taijuan Walker is scheduled to toss a bullpen session Sunday after playing catch on Thursday. Walker is on the 15-day DL with right shoulder inflammation. ... Royals 2B Omar Infante was not in the lineup for the second consecutive day due to back spasms. Manager Ned Yost said the team doesn't think Infante will have to go on the DL. Infante is day to day.
