Minnesota took the rubber match of the three-game set, snapping the Astros' three-series home winning streak.
Mauer's long ball on a 2-2 pitch into the Astros bullpen prevented Houston from matching its win total of 51 from last season.
"I would like to have that [pitch] back," Olberholtzer said. "Challenged him there with nobody on to start the inning and he made me pay for it."
Houston had won five straight with the southpaw on the bump. Wednesday's effort gave him eight quality starts in his last nine outings since settling back in at the big league level after shuttling between the Minors during May and June.
He delivered another gem, with a final line featuring seven innings of six-hit ball to go along with four strikeouts and no walks.
"I doubled up well inside and up in the zone, threw a lot of backdoor curves early in the count and was able to finish with my changeup," the lefty said. "Kept them off balance most of the way."
But in a startlingly breezy weekday afternoon contest -- the first seven innings clocked in under two hours -- the 2-2 pitch Olberholtzer left up and in for Mauer meant he wouldn't be as good as Twins hurler Kyle Gibson.
"I always get up for [these] type of games, a good pitchers' duel with everything moving," Olberholtzer said. "[Gibson] was just awesome for them."
The young righty absolutely flummoxed a Houston lineup that had averaged a shade over five runs in its previous six contests and had perhaps the hottest hitter in baseball, Chris Carter, batting third.
Only Carter's eighth-inning single that drove Jose Altuve in touched Gibson, who exited the game immediately after. He lasted 7 2/3 innings and nabbed his second win of the season against Houston.
"Gibson was in command. … He kept pouring it in there and didn't let them breathe much," said Twins manager Rod Gardenhire. "I knew he was disappointed because he didn't finish it. I knew by the seventh inning he wanted to finish it. A great performance."
Gibson compiled a 0.61 ERA when facing the Astros this season, thanks also to his seven-inning shutout at Target Field against them back in June.
Even though he didn't launch another homer, Carter still went 2-for-4 with a pair of base hits, his first hits against the Twins this season that didn't leave the ballpark. He's now recorded an RBI in seven straight games, and the slugger is tops in the Major Leagues with 37 runs driven in since July 1.
The Astros weren't without other chances. A leadoff hit by Robbie Grossman preceded Carter's single in the first, but Dexter Fowler and Jon Singleton flew out to end the threat.
Singleton kickstarted a fourth-inning opportunity, though he was helped by Eduardo Nunez's catching error. With two on and one out again, two more lazy outs through the air doomed Houston.
In the seventh, a Singeleton walk and Carlos Corporan's single only set up a 5-4-3 double play on Matt Dominguez's ground ball. Jake Marisnick then popped out to center field.
"Really felt like we could have capitalized for maybe a few runs in that spot," Olberholtzer said. "Carter's RBI came an inning too late. We were just always working from behind late."
Manager Bo Porter said there was no denying Gibson's stuff on Wednesday, but that doesn't excuse some of the home team's inability to push the runs across.
"[It was] a little bit of both," Porter said. "I felt like he really threw the ball well, with a power sinker, threw his cutter in on lefties and the slider was short and quick. That said, we missed some great opportunities."
Moments after that rally fizzled, reliever Josh Fields promptly surrendered the ultimate winning runs on Kennys Vargas's two-run single with the bases loaded. Fields has now allowed eight runs in his last six innings of work.
"Just those elevated balls up in the zone that have hurt him," Porter said. "He's just not getting the swing and miss or the late life on those [high fastballs] he was getting [last month]."
Despite the loss, there were positive signs for the Astros as they head off to Boston to start a 10-game, three-city road trip.
Fowler returned to action for the first time in six weeks and went 1-for-3 and showed no signs of limited mobility in center field after an intercostal strain. Marisnick scooted over to right and easily snared a few sharply hit liners in his first Major League action at the position.
"Whenever you are athletic and have three guys in the outfield capable of playing center field, we're improved -- cutting balls off, getting to them in the air," Porter said. "You got a glimpse of that today."
The Astros and Twins split their season series, with each team taking two out of three in the opposing team's park. Houston is now 12-13 this year against the American League Central.