...he goes down faster.
Two things here. First, when knocked down for the fifth time with a normal punch, Tyson can get a very low refill, enough to knock him down with a dodge, stun, uppercut. This makes getting the second star in phase 1 (is it still phase 1 when it's in round 3?) unnecessary.
The other is that starting in... I think it was 2:00 R2... Tyson can be guttered.