Buxton scored the winning run in the top of the ninth to give the Twins a 4-3 victory that ended a five-game slide.
He went 0-for-4 Sunday but reached base in the ninth on a fielder's choice before coming around to score from first on Eddie Rosario's double to center.
The Twins announced their plan to select Buxton's contract from Double-A Chattanooga on Saturday. The 21-year-old batted ninth and started in center field in Sunday's win.
"Everyone hopes that he'll come in and make it tough to think about sending him back,'' manager Paul Molitor said before the game. "We have a lot of confidence. ... He's an exciting player, but he's still learning how to hit.''
Minnesota outfielder Torii Hunter is serving a two-game suspension for his uniform-tossing tirade at the umpire, and Aaron Hicks was scratched from his spot in center Saturday because of an elbow problem.
To make room for Buxton on the 25-man roster, the Twins placed Hicks on the 15-day disabled list before Sunday's game.
"It was the right time to try to get us a center fielder,'' Molitor said.
Buxton is No. 3 on ESPN Baseball Insider Keith Law's latest list of top prospects. The No. 1 player on that list is Correa.
In 59 games for Chattanooga this season, Buxton hit .283 with 12 triples and scored a Southern League-high 44 runs. He also had 37 RBIs, 20 stolen bases and six home runs.
Buxton kept up his rapid ascent to the majors in the past year despite a variety of injuries, having sustained a concussion, a wrist problem and a dislocated finger.
He played Friday night at Birmingham and was out of the lineup Saturday. He went 2-for-4 in that last game in Double-A and, showing an aggressive running style, was thrown out on the bases for the second straight day.
Drafted from high school in Georgia, Buxton has been on a fast track to the big leagues. With two-tone hair, he already has star power. On Friday night, he tapped both the Barons catcher and plate umpire on the shin guards when he walked into the batter's box to lead off the game then easily beat a chopper to the shortstop.
The surprising Twins are 34-28 and in second place in the American League Central.
The Associated Press contributed to this report.