Easy strat for this that works on all 3 phases of the boss.
Hit him 3 time with the

punch, the walk away from him when he falls to the ground. He will jump back up and teleport to you, as soon as you see him walk either directly up or down to dodge his attack.
Rinse and repeat that for the whole fight and you'll be sorted.
Only place where you might have slight trouble is during the last phase where he may do another attack after his punch when he teleports. Just bring some food to heal up just to be on the safe side.