Izzy parlayed that into seven saves, which lifted him to that milestone No. 300 for his career this week in San Diego.
And now Izzy will hand that closer's role to Bobby Parnell -- as soon as Sunday afternoon, in fact.
But on a wild late Saturday afternoon at Citi Field -- after firefighters had extinguished thick black smoke that billowed from an automotive shop across the street from the stadium -- K-Rod and Isringhausen shared the late-inning center stage.
In his first relief appearance as a visitor at Citi Field, K-Rod recorded a pair of outs, walked Ruben Tejada, then allowed a game-tying double to Josh Thole and two-run homer to Angel Pagan. A half-inning later, though, with the Mets up 9-7, Isringhausen allowed all four Brewers he faced to reach.
Izzy departed with the Mets clinging to a one-run lead and the bases loaded. Manny Acosta eventually allowed all three inherited runners to score. Milwaukee won 11-9 to drop the Mets five games under .500 for the first time since June 3.
Afterward, manager Terry Collins expressed frustration with how six Brewers who reached on walks or a hit by pitch all scored. Yet Collins again applauded the Mets' resolve in rallying from a one-time six-run deficit.
"We lost the game, but in my estimation, it didn't go to waste," Collins said.
Of course, Collins needs results in order to validate what the Mets have accomplished this season, and to guard against a late-season free fall eroding a generally positive season.
Victories will be no easy task. After completing a series with the NL Central-leading Brewers on Sunday, the Mets head to Philadelphia to face the NL East-leading Phillies. The Mets then return home to face the wild-card-leading Atlanta Braves.
Isringhausen felt terrible about Saturday's meltdown.
"No excuse," Isringhausen said. "I warmed up in the bullpen fine. I got out there and I just lost it. I couldn't find the strike zone. Terry did the right thing when he did taking me out. Like I said, it's on me. When guys come back, and our team comes back, and I go out there and do that, it's just a debacle. I mean, it ranks right up there as one of the worst ones of my career."
Entering for the bottom of the eighth, K-Rod was greeted rudely by the Citi Field faithful, but that was to be expected.
"Just another team. Another ballclub," Rodriguez insisted about his own emotions. "That's how I see it. I've got a job to do. When you're home, the home crowd is going to give you a [positive] reception. When you're on the road, they're going to boo you. Simple as that."
Rodriguez professed no rustiness or injury-related issues, but that might have been spin. K-Rod injured his left leg beating out an infield single a week ago and had not pitched since last Saturday. He still had significant discoloration on the inside of his left leg from a muscle pull, and moved around gingerly in the clubhouse, after facing the Mets.
K-Rod, trying to protect a one-run lead, regretted walking Tejada with two out to start the rally.
"I had him 0-2 and walked him," Rodriguez said. "Pretty much I put myself in that situation right after that walk with two outs."
Still, K-Rod thought center fielder Jerry Hairston Jr. had caught Thole's ensuing shot to center. Instead, it went off Hairston's glove for a double and Tejada scored the game-tying run from first base.
"I thought it was a ball that had been caught," Rodriguez said. "I didn't notice the ball was on the ground. When I saw the runner [Tejada] already turning to second, and then second to third, I knew he was going to score easily after that."
As for serving up the two-run homer to Pagan, K-Rod said he just left a changeup up. Just as Isringhausen had done, Rodriguez made no excuse.
"It was right down the middle," K-Rod said. "Actually, the ball didn't do anything. It just flattened out -- right down the middle. Twice before, [throwing] that [changeup], the ball dove. So that means I finished it. And that one I didn't finish. That's why it stood up right down the middle."
Said Collins: "I'm disappointed the way it ended. No question about it. But they played nine innings, and that's what I asked them every day -- to play nine. Go out there and play 27 outs as hard as you can and see what happens."