That Tim Simms is a right bugger, he really gets your thumbs bleeding on the top difficulty level.
Just never go toe to toe with him. Keep him away with the left-right-left-right combos to the head and stomach and then keep moving. Once he's used up his punch power a bit, maybe go for a super punch. As always with super punches try to time it so they walk into it, then follow in with combos. It's tuff, but very satisfying when you make him eat canvas.