Triathalon knows he sucks at hand to hand combat, which is why he concentrates on his speed and agility, he's more at home in the air hopping around than he is on the ground seemingly. By that virtue alone he'll give Shatterstar a bit of trouble, but when Shatterstar finally connects and gets Triathalon, it's over for him.
I thought Triathalon had great potential, but was handled a bit poorly. Busiek forced a race issue into the book and handled it tritely--which is my only real complaint about the book. His connecting Triathalon to the 3D-Man was awesome though.