– Whoever was sitting 410 feet away from home plate, high in the upper deck of Rangers Ballpark, made a big mistake when Justin Morneau’s seventh-inning home run landed in their lap. They threw it back on the field, “so I didn’t have to trade anything for it,” Morneau said.

That’s a valuable souvenir already, considering it was the game-winning blow in what was easily the Twins’ most improbable victory of the season — a 3-2 victory over Cy Young contender Yu Darvish, who entered the seventh inning with a no-hitter intact, until Chris Herrmann and Morneau changed all that.

It’s also Morneau’s 221st home run, propelling him past Tony Oliva and into third place in Twins history.

And it might be, could be, the last baseball that Morneau belts as a Twin, the final heroic blow in a decade that had more than a few. The deadline for postseason contenders to acquire upgrades like Morneau comes Saturday night, and if the Orioles, Pirates or even these Rangers wondered if he can reach the seats against baseball’s best, well, some poor upper-deck sap had the evidence in his hand and threw it back.

“If it happens, I’m going to somebody who wants me and feels they can use me in a pennant chase or a playoff drive. And if not, I’m here and I know I’ll be here for the rest of the year,” Morneau said. “Either way, it’s a good situation.”

That’s as opposed to facing Darvish. The runaway major league leader in strikeouts toyed with the Twins for six innings, facing the minimum 18 hitters and whiffing 10 of them with sliders that seemed to veer in and out of the strike zone.

Every Twin but Morneau trudged back to the bench at least once after facing Darvish, who appeared to get stronger as the night wore on.

Second baseman Brian Dozier, whose diving stops of what looked like RBI grounders had already saved two runs, broke Darvish’s spell by drawing a leadoff walk in the seventh. And then Herrmann — whose parents and younger brother, who drove up from their home in suburban Houston, were watching him play a big-league game for the first time — gave them a memory that ranks up there with Morneau’s.

He settled in, watched two pitches go by out of the zone, then pounced on an inside cutter.

“My main goal was to try to get [Dozier] over to second base. A 2-0 count, that’s a hitter’s count. He threw a pitch middle-in and I turned on it,” said Herrmann, who seemed shocked when it landed three or four rows deep in the right-field seats. “It’s kind of cool to hit a home run the first time they see me in the majors.”

The sweltering crowd around Ronnie, Bobbi and Scott Herrmann was shocked into silence, though, the energy suddenly drained. Maybe it happened to Darvish, too.

“I feel like after the home run, he kind of got rattled,” Herrmann said. “Things just went haywire for him.”

“Haywire” must be Texan for slider in the middle of the plate, because that’s what Morneau got on a 2-1 count. Between innings, Morneau said he reminded everyone in the dugout that Darvish was pitching a no-hitter. And his home run, breaking a 1-for-25 slump, suddenly, impossibly, made a winner — for the second time in his 25 career starts — of Liam Hendriks.

The Aussie righthander didn’t have no-hit stuff, but he was impressive in facing one of the American League’s most potent offenses, limiting Texas to two runs, one of them unearned, in six innings.

“Liam was fantastic,” said Herrmann, who caught him. “One thing we’ve been working on is keeping the ball down, and he did a great job of it.”

But Hendriks appeared most of the night to be a mere footnote to Darvish’s Cy Young campaign. The Japanese righthander struck out 11 Twins, giving him 236 for the season and 63 in August, the first American Leaguer to whiff more than 60 in a month since Johan Santana did it for the Twins in July 2004.

Then Herrmann and Morneau changed things.

“That was big. We needed that,” Morneau said, one day before he learns if someone else needs him, too.