This was Alan's first time winning the mirrorball trophy as a pro on the show.
Pop star and Fifth Harmony member Ally Brooke and partner Sasha Farber finished the season in third place, and country singer and former American Idol runner-up Lauren Alaina and partner Gleb Savchenko claimed fourth place.
The four celebrity and professional pairings who made the finals competed in two rounds of competition on Monday night -- an encore of each celebrity's breakout performance from earlier in the season as well as the fan-favorite freestyle, which has no rules and typically exceeds expectations.
Despite not being crowned champions, Ally and Sasha topped the judges' leaderboard in first place on finale night with a perfect total score of 60 out of 60 points.
Kel and Witney finished in second place with 59 total points, Hannah and Alan placed third with 58 points, and Lauren and Gleb landed in fourth place with 57 points.
Ally and Sasha first took the stage with their "repeat dance," which was a jive to "Proud Mary" from Week 4 of the competition. They received 30 out of 30 points from the judges for this dance.
Len called the jive "fantastic," and Bruno said the couple had "succeeded on every level."
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"There is has been so much controversy, but that is why you are here tonight!" Carrie Ann expressed, adding, "You are brilliant."
Ally and Sasha -- who had been saved by the judges multiple times this season, which even resulted in frontrunner James Van Der Beek's ouster -- followed their jive up with an energetic freestyle set to "Conga" by Gloria Estefan that included a lot of sexy salsa moves and earned 30 additional points from the judges.
"Unleash the star power!" Bruno yelled after the performance.
"I've seen every single freestyle ever in the history of Dancing with the Stars; I've never seen anything like that... For such a little girl, you are such an explosive performer," Carrie Ann told Ally.
Len loved how the music was recreated in every movement Ally and Sasha made.
Kel and Witney initially danced their High School Musical-inspired jazz routine from Week 5 again, and the pair received a perfect score of 30 judges' points.
Carrie Ann said Kel was "spot on" in the delivery of every dance move, and Len could tell Kel had given the dance his all. Bruno also complimented Kel's "musicality."
For Round 2, Kel and Witney took the stage with a hip-hop inspired freestyle to "Jump" that got faster and faster in tempo as the song progressed.
Bruno called the routine "exhilarating," and Carrie Ann said her "inner fly girl" was "so happy" after that performance.
Len didn't want to be the party pooper, but he insisted Kel's freestyle was similar to the first dance he did of the night. Len wished Witney had incorporated more dance styles into the choreography of their final routine.
"It was the same meat with a bit of different gravy around it," Len noted, as the audience booed loudly.
Kel and Witney, however, still received 29 points for the freestyle, andDancing with the Stars co-host Erin Andrews said it was one of the best freestyles she had ever seen.
Hannah and Alan's first performance of the night was a new and improved version of their Week 2 Viennese waltz.
Len appreciated Hannah's "lovely, sweeping movement" across the floor despite a little mess-up in her foot action, and Bruno noticed a much more "confident, engaging and radiant" woman on the stage than in prior weeks.
"For me, that was your best dance of the season. There was something so magical about what you just did," Carrie Ann argued. "Sometimes the greatest struggles bring the greatest rewards."
After Alan called his time with Hannah onDancing with the Stars the most "exceptional experience" he's ever had, the judges gave the couple 28 points -- which included a 10 from Carrie Ann.
Hannah then brought the ballroom down with her freestyle set to a mashup of songs including "Girl On Fire" and "Hollaback Girl." Hannah had many moments to shine when she danced solo with other female pro dancers.
Len complimented Hannah on her sharp and crisp moves, and Bruno said she brought drama and sexiness to the stage.
Carrie Ann told Hannah that she's living her best life and her freestyle with Alan was "victorious," despite one little stumble she had decided to overlook.
With that being said, Hannah and Alan received 30 points from the judges, Hannah's first perfect score of the season.
For the first round of competition, Lauren and Gleb chose to do an encore performance of their Week 4 foxtrot to "Jolene." The couple earned 27 points from the judges for the routine.
Carrie Ann said Lauren had improved as a dancer but she didn't really feel the emotion from her this time around. Carrie Ann thought Lauren was "holding back" a little bit.
But Lauren and Gleb took Round 2 by storm by dancing a country-themed freestyle that even included a little line dancing. Lauren and Gleb also received a perfect score of 30 points for the dance, and those were Lauren's first 10s ever.
Carrie Ann said it was the perfect freestyle for Lauren, who had been open and vulnerable all season long, and Len said the performance was "full of entertainment." Bruno added that Lauren's line dancing was "delicious."
Dancing with the Stars also featured a live performance by Ne-Yo and Pitbull featuring the entire Season 28 cast.
In addition, American Idol judge Lionel Richie announced Layla Spring will receive a Golden Ticket to Hollywood, CA, where her journey on the show's 18th season will continue.
Layla had competed against fellow former Idol hopefuls Shawn Robinson and Logan Johnson in a special second-chance competition that aired during the American Music Awards on November 24.
(Layla, Shawn and Logan auditioned for previous Idol seasons but didn't quite make the finals cut).