Over the first six innings, Iwakuma allowed just three hits, handling the Brewers' lineup with ease. But he couldn't make it out of the seventh, finishing the game after 6 2/3 innings, giving up six runs on nine hits.
The Mariners couldn't get much going against Brewers left-hander Tom Gorzelanny and the bullpen. A fifth-inning double by Dustin Ackley and a single by Nick Franklin followed by a walk of Kyle Seager in the eighth put runners in scoring position for Seattle, but the Mariners were unable to capitalize on their limited opportunities.
The Mariners have struggled against left-handers all year, scoring only 134 runs compared to 337 against righties. As a team, Seattle has a .670 OPS against lefties compared to .739 against righties. Gorzelanny was particularly dominant.
"He threw the ball well, you can't take anything away from him," acting manager Robby Thompson said. "He shut us down. Once again, we struggled against a left-handed pitcher on the mound, so we've got to do a better job of that."
Gorzelanny struck out the side in the second inning, sandwiched around a Michael Morse single. The Milwaukee starter allowed just three hits in seven innings while striking out seven batters. Ackley was the lone bright spot for the Mariners offensively, going 2-for-3. He is hitting .239 since being recalled from Triple-A Tacoma.
For the second straight night, the Brewers batted around in a wild inning to put the Mariners away. In Friday's series opener, the Brewers took advantage of Mariners errors and a grand slam by Yuniesky Betancourt to score five runs in the fifth.
On Saturday, poor fielding by the Mariners again paved the way for a bases-clearing Brewers blast. Carlos Gomez led off the inning with a bunt single up the first-base line. Justin Smoak fielded the ball and ran toward the base, but Gomez dived around the tag to reach safely.
On the play, Iwakuma appeared to suffer a minor tweak. He lunged for the ball initially on contact, but then pulled up immediately while grabbing at his back.
"I don't like to admit, but ever since that play, my pitches were a little bit up. I don't like to make excuses or anything, but I'm sure it had something to do with it," Iwakuma said.
Gomez advanced to third when shortstop Brad Miller made an ill-advised throw to first on Caleb Gindl's single. Khris Davis scored the run on a fielder's choice. Seager fielded his sharp grounder at third base and threw home.
Catcher Humberto Quintero caught Seager's throw in time, but Gomez barreled into the backstop, knocking the ball loose to score the run and avoid the out. Quintero appeared to be injured on the play, but returned after a short delay.
When Gomez stepped to the plate for the second time in the inning, Quintero had sharp words for him.
"I don't mean to hurt any player, but if he's in front of the plate, what am I going to do?" Gomez said. "You don't even have a second to think, you run over [him] and after that, the guy says, 'That's not a clean play.' I say: 'What are you talking about? What do you mean? You're in front of the plate.'"
Quintero, Gomez said, argued that he'd given Gomez an opening to slide. Gomez disagreed.
"He's mad," Gomez said. "He talked to me in bad language, and I talked to him back, too. I said: 'Hey, come on. Keep it cool. You're in front of the plate, what do you want me to do?' And especially, I know what kind of catcher he is. I know he likes to drop the knee. I think it's best to defend myself."
With runners on the corners, Gennett hit his second home run of the season, putting Milwaukee up 6-0 with no outs. Right Fielder Michael Morse almost robbed Gennett of the homer, but was unable to reel in the catch.
"I feel like I had a good chance on it until I hit the wall and it kind of jarred my wrist back," Morse said.
Lucas Luetge struggled in the ninth, as Milwaukee tacked on four more runs on six hits against the left-hander.