Fallon kicked things off with House of Pain's "Jump Around," but O'Neal proved to be stiff competition when he topped the host's performance with his own rendition of Bobby Brown's "My Prerogative."
"I'm bringing 1988 back," the NBA star joked as he ditched the standing mic for a mic headset and invited audience members up to the stage to dance with him. Musical guest Pitbull made a surprise appearance during O'Neal's set.
The two competitors made nice towards the end of the battle, as O'Neal forced Fallon to join him for a duet of Elton John and Kiki Dee's "Don't Go Breaking My Heart." O'Neal, mouthing Dee's lines, got affectionate with the host, giving him a peck on the cheek and a love pat, and lifting him into his arms.
The Tonight Show is airing from Orlando, Florida this week for the opening of Fallon's new ride at Universal Studios, The Race Through New York Starring Jimmy Fallon.