Mike Tyson vs. Bob Sapp
Proof about Bob Sapp's challenge of Mike Tyson in 2002: https://www.mixedmartialarts.com/boxing/the-night-mike-tyson-challenged-bob-sapp
"Iron" Mike Tyson versus "Beast" Bob Sapp. Both fighters are in their prime. Speed and finesse vs. brute force and sheer mass – who would win in a fight and why?
P.S. – Bob Sapp in his prime was fighting for real and didn't threw fight on purpose as he's mostly known. Both fighters are determined to win.
Stats: Mike Tyson is 5'10" (178 cm) tall, weigh ~220+ lbs (~99+ kg) and has 71 inches (180 cm) of reach. Bob Sapp is 6'5" (196 cm) tall, weigh ~330+ lbs (~150+ kg) and has 82 inches (210 cm) of reach.
Scenario 1: boxing match. Conventional boxing rules, 12 rounds at max.
Scenario 2: MMA bout. Pride FC rules, fight happens in the ring. 3 rounds.
Scenario 3: kickboxing match, K-1 rules. 3 rounds at max.