"To have such incredible support, especially from my mom who rallied everyone, I feel so grateful," the star told the magazine after the show. "It means so much."
Willis and Chmerkovskiy earned a perfect score with their foxtrot and paso doble to Angus & Julia Stone song "Big Jet Plane" before being crowned the winners. The pair beat out Riker Lynch and Alison Holker and Noah Galloway and Sharna Burgess, who came in second and third.
"After three months of dancing every day, my favorite thing is getting to dance with Val," she said of the couple's final performance. "This was the last time on this stage that I got to do that, so I wanted to make it the best I possibly could."
Willis was supported by Moore, father Bruce Willis, stepmother Emma Heming and sisters Scout and Tallulah Willis throughout the competition. Celebrities such as former stepfather Ashton Kutcher, Miley Cyrus and Gwyneth Paltrow also cheered on the actress on social media.