SEATTLE -- Hisashi Iwakuma has learned over the years what it means to adjust and pitch without your best stuff. And on Tuesday night, that meant leaning far more than usual on a big, looping curve ball that kept the Pirates off balance en route to a 5-2 victory for the Mariners at Safeco Field.
Iwakuma continually dropped the 70-mph curve in for first-pitch strikes, getting ahead in counts and then using his other weapons to hold the Pirates to two hits over six scoreless innings before giving up a pair of runs in the seventh.
His final line of six hits and two runs with one walk and four strikeouts over 6 2/3 innings helped Seattle win for the third time in its last four outings and put Iwakuma at 7-6 with a 4.34 ERA on the season.
"There were a lot of slow curves in there," said manager Scott Servais. "It kept them off balance. He probably didn't have his sharpest stuff. The splitter was just OK. But he got the breaking ball over early in the count and evened up a lot of counts when he was behind with it, which was really key for him tonight."
The 35-year-old right-hander acknowledged he didn't have his normal sharpness in the bullpen before the game, so he went with what was working.
"I was able to go back and forth with the curveball, just to kind of change speeds, keep the ball down and also steal strikes. So it worked out well," Iwakuma said through translator Antony Suzuki. "It was part of our plan before the game. But more than just that, Chris [Iannetta] behind the plate had a lot of confidence in it. So he called it a lot and I didn't shake and it worked out well."
With Felix Hernandez on the disabled list, Iwakuma has assumed more of the No. 1 starter mantle, and he's responded well, going 6-2 with a 3.78 ERA in his last eight starts.
It helps that he has the experience to tap into different ways to work hitters even when his splitter isn't diving as much as normal and his fastball is ticking in the upper 80s.
"This happens a lot at this level," he said. "Sometimes you have your stuff; sometimes you don't. It's been like that since Japan. The experience does help. Making sure what you need to do and making sure you don't go away from the game plan helps out a lot, and it did today, too."
Not until the seventh inning did the Pirates finally start to zero in on Iwakuma's offerings and he said that was a combination of him tiring and the Bucs timing him up.
"I did get a little tired," he said. "The ball got up in the zone, but I was still able to get out of a few jams and I'm glad that we won."
Greg Johns has covered the Mariners since 1997, and for MLB.com since 2011. Follow him on Twitter @GregJohnsMLB and listen to his podcast. This story was not subject to the approval of Major League Baseball or its clubs.