The singer and actress was paired with professional dancer Jenna Johnson in the U.S. TV show's first-ever same sex couple, and the pair won high praise from viewers and judges alike for their Quickstep.
Their routine saw them awarded 29 points out of a possible 40, and they were also the only pair to be given an eight from any judge.
"It was so cool! I didn't know when it happened!" JoJo told Entertainment Tonight after the show. "When Tyra (Banks, host) said it was the highest score of the night, I lost it."
Just behind JoJo, with a score of 28, was Amanda Kloots and her pro partner Alan Bersten. Amanda told the judges that she could feel the presence of her late husband Nick Cordero, who died after losing his battle with COVID-19 earlier this year (21), as she took to the dancefloor for her tango.
Olympic gymnast Suni Lee and her partner Sasha Farber tied with Amanda on the leaderboard, with 28 points, while Spice Girls star Mel C found herself in fourth position after her Cha-Cha-Cha to the tune of "Wannabe".
At the bottom of the leaderboard was "The Karate Kid" actor Martin Kove, who failed to impress the judges with his Paso Doble, and earned just 13 points out of a possible 40.