The rest of the Desert Dogs' bats came alive in the ninth, adding five insurance runs as they defeated the Javelinas, 6-0, at Surprise Stadium.
Mitchell was the first batter Dufek faced. Because of that, Mitchell said he figured the right-hander would want to start him with a strike and was ready when Dufek obliged with a fastball over the heart of the plate.
"I got a pitch I can handle and was lucky enough to get good wood on it," Mitchell said.
Mitchell hasn't had much luck this season. The White Sox No. 10 prospect began his season at Triple-A Charlotte, but struck out 27 times in 14 games and was sent down to Double-A Birmingham. He continued to struggle there, hitting .174, and missed a month due to a strained oblique.
After such a disappointing season, Mitchell has found more success in the Arizona Fall League. He went 2-for-3 with two runs and two walks Thursday to raise his batting average to .308.
He said he wants to use his time in the AFL to become a more consistent player.
"It was kind of a rocky year to say the least," Mitchell said. "I want to come out here and just be consistent every day. I want to try to improve that part of the game because that's what it takes to be a big leaguer."
Mitchell's home run helped support another exceptional effort from the Desert Dogs' pitching staff. They held the Javelinas to two hits and threw their fourth shutout of the season and second in as many days. After just 12 games, Glendale is two-thirds of the way to tying the league record of six shutouts, set by Scottsdale in 1998.
Right-hander Stephen McCray, the reigning AFL Pitcher of the Week, allowed one hit in four innings to start the game. The four relievers who followed him combined to allow one hit and two walks in five innings.
Mitchell said McCray, his White Sox teammate, was impressive again Thursday.
"He threw the ball well and controlled the zone," Mitchell said. "When he's doing that, he's lights-out because it's tough to square balls up against him. In his last two outings, he's done that well."
Second baseman Orlando Calixte, the Royals' No. 8 prospect, got the lone hit off McCray. Calixte finished the game 1-for-4 with a stolen base. Catcher Austin Hedges, the Padres No. 2 prospect, had Peoria's only other hit.
For seven innings, the Javelinas pitchers were nearly as good as the Desert Dogs. Right-hander Brandon Maurer allowed no runs and two hits in four innings. Ken Giles and Dennis O'Grady combined for three more scoreless innings before Dufek gave up Mitchell's blast.
The Javelinas committed three errors in the ninth inning, leading to five runs, all unearned, by the Desert Dogs.
Glendale first baseman Max Kepler and Mitchell were the only players with multiple hits. Kepler, the Twins' No. 8 prospect, went 2-for-4 with a double and a run.
The Desert Dogs have now won back-to-back games after snapping a four-game losing streak on Wednesday. Mitchell said they have played well in all aspects of the game the last two days.
"We didn't swing the bats for a couple days there, so to swing the bats a little bit better the last few days is good," Mitchell said. "Our pitching has done a good job and kept us in games. It's been a total team effort the last two days."