When you catch him with a left like that, follow him fast by drawing your rear leg up to your front leg and flying knee off the front leg as he squares up, he wont get up. He will be looking to keep his head away from more fists with distance and leaning back is a mistake as is going straight back.

He is so open to straight front kicks right between the elbows all the time. If you can bang fast with your legs and send a foot into his mid riff as he runs forwards he is gone. He is open for business and he hasnt a cool head so time him coming,or kick up from under your block, if you hide a front kick coming from under your lead arm he wont even see what happened.

Practice what youre good at ,dont over think it and you'll make the spaces to work in.

And good luck.