Milligan lifted a sacrifice fly to give the Lynchburg Hillcats a 5-4 victory over the Winston-Salem Dash and their second Carolina League championship in four years.
"It was an amazing night, winning in extra innings to cap it off," said Hillcats shortstop Nick Ahmed, who went 4-for-5 with three doubles and was named MVP of the best-of-5 series. "It was one of the most fun, most intense baseball games I've ever played in, probably the most. It was just great to win it on our home field."
Lynchburg loaded the bases in the 11th without hitting the ball out of the infield. Matt Weaver reached on an infield single and Braeden Schlehuber was safe when reliever Bryan Blough fielded his bunt and made an errant throw. Mycal Jones greeted Steven Upchurch with a bunt single, setting the stage for Milligan.
The Braves' sixth-round pick in the 2008 Draft sent a fly ball to deep right field, easily scoring Weaver and setting off a wild celebration at Calvin Falwell Field.
"It was an emotional game, kind of up and down throughout," said Milligan, who came on as a pinch-hitter in the eighth. "But as soon as we got those bases loaded with no outs, we felt pretty good there in the last inning. I got a pitch I like to hit and we were fortunate to get the go-ahead run there.
"I started off slow in the series. In this game -- and especially that last at-bat -- I didn't try to do too much. I was just trying to drive the ball up the middle and I got a pitch up in the zone. Luckily, I got it deep enough for the guy to score."
With the Dash taking a 4-3 lead into the ninth, the Mills Cup Finals appeared headed for Game 5 for the first time since 2005. But Edward Salcedo reached on a one-out double and Michael Spina -- making his first start of the playoffs -- sent a line drive over the head of right fielder Michael Earley to force extra innings.
Winston-Salem ran into a buzz saw in Hillcats reliever John Cornely (2-0). The 23-year-old right-hander struck out seven of the 11 batters he faced over three hitless innings to get the win. In eight appearances following a promotion from Class A Rome, he's allowed one run on two hits while fanning 16 over 13 2/3 innings.
"Our pitching staff has done an amazing job this year; [they're the] best pitching staff in the league, by far," Ahmed said. "John Cornely was absolutely lights-out. They weren't even putting good swings on him. He was just blowing balls by people."
Ahmed, Atlanta's No. 11 prospect, doubled in the first, sixth and eighth innings, accounting for Lynchburg's only hits heading to the ninth.
Two of his doubles came off White Sox No. 6 prospect Scott Snodgress, who yielded three runs on three hits and struck out five over six frames.
David Herbek doubled, walked twice and scored a pair of runs for the Dash, who claimed the Southern Division in both halves of the regular season and owned the best winning percentage among full-season teams in the Minor Leagues (.630).