Round 1:
Goomba vs. Whomp
The battle begins, and Goomba uses its superior speed to run circles around the much bigger (and much slower) Whomp.  Whomp turns dizzily, trying to keep up, and Goomba seizes the opportunity as it catches Whomp facing the wrong direction, and immediately leaps and kicks the sore crack on Whomp's backside.  The stone monster groans in pain, then falls backwards and squashes the helpless Goomba beneath its bulky rock body, winning the match through simple luck.

Whomp advances...