HOUSTON – When Tyler Duffey describes Sunday's start to his grandchildren someday, the magical way he performed for dozens of family and friends, the uncanny way he outpitched the Astros' unsinkable ace, his fairy-tale story probably will end with him walking off the mound in triumph — well, close to it — to a warm ovation in the seventh inning.

Let the kids think the Twins lived happily ever after.

In reality, though, Duffey watched from the dugout as the normally shut-down Trevor May allowed the inning, and Duffey's victory, to blow up in his face, with Jed Lowrie launching a down-the-middle changeup with the bases loaded into the third row in right field. Lowrie's grand slam sparked the Astros to an 8-5 victory and sent the Twins to Kansas City still 1 ½ games outside the playoff picture.

"One guy [is all] I needed to get out. I faced four, and didn't get any of them out," May chastised himself after surrendering Duffey's 2-0 lead. "In short, I blew it."

The Twins were shocked by that fact, given that May has adapted so well to his new bullpen role. He had thrown shutout baseball in 16 of his past 17 relief outings, and never had let an inherited runner score a meaningful run.

"He's been so good, it's hard to find fault," Twins manager Paul Molitor said. "I don't know if he was overamped or what."

Maybe so, May said; it's as good a reason as any for his problems throwing strikes. Coming in with two runners on base and two outs, he immediately walked pinch-hitter Preston Tucker on four pitches. He forced Jose Altuve to hit a dribbler toward third base, but he beat Trevor Plouffe's desperate, on-the-run throw to score a run.

Then came Lowrie, who swung and badly missed at May's first pitch, a changeup. Two fastballs were outside the zone, and May decided to try another change.

So did Lowrie.

"It was right down the middle. It wasn't where I wanted it," May said. "I was going by the swing before — he was way out in front of it. I was just trying to get a popup or a swing-and-miss or something softly hit somewhere. But it stayed up, and he yanked it over the fence."

The Astros added three more runs in the eighth, on a home run by Jake Marisnick, making the Twins' own two-run ninth merely an encouraging footnote.

Duffey, pitching a few miles from his childhood home for the first time since college, took the disappointment stoically.

"That's baseball. He's just been dominant, and sometimes it just happens," Duffey said. "He'll go out there and strike out three next time."

Duffey was mostly brilliant, outdueling Cy Young Award candidate Dallas Keuchel for six innings and earning noisy ovations from his several dozen friends and relatives in the crowd after every shutout inning. He matched his career high with eight strikeouts and four times pitched out of trouble after giving up leadoff hits, two of them doubles.

"That was impressive. Those are tough runs to prevent, particularly with the doubles," Molitor said. "But he just had enough velocity and location to make that curveball — I don't know how many outs he got with it, but it seemed like a vast majority."

Duffey wasn't nervous, or at least not once he started pitching, he said, and when the Twins handed him a 2-0 lead on solo home runs by Brian Dozier and Eduardo Escobar, he seemed to be headed toward a memorable victory. Certainly the Duffey-heavy crowd by the Twins' dugout, which included his father and his 93-year-old grandmother, thought so.

"It's hard not to hear it — the people were all there in the front row," Duffey said. "But leaving guys on [for May], I was still a little upset with myself."

He needn't be, Molitor said.

"I was happy for him. He was pretty much in control. We know when he's got his good curveball, he's going to be tough on righties and lefties."

Too bad those stories don't always have happy endings.