Funny or not I speak the truth. Technique is vital, followed by speed then strength. This is the foundation of a proper strike. One well placed, properly executed strike can defeat anybody. A 150 pound man could knock out Mike Tyson cold with a single elbow to the forehead. Hell, he could kill him actually.

How big is he, exactly, and how strong are you? Do you think you can lift him? If you can lift the guy, a headlock is a total sucker hold.

That may be impressive but remember that technique is the most important aspect of a good strike, followed by your speed, then your muscle strength. As I said, practice your strikes to improve your technique and increase your speed. When I say practice, I mean throw the strike properly thousands of times in the coming days. Make sure your form is correct; having a trained fighter to instruct you is ideal but you may have to settle for online videos with such short notice. Be careful not to strain yourself beforehand. Again, good luck with the fight.

big weight difference. 100lb is a lot in fighting. your punches will not be very significant to his body since he weighs alot more than you. what i recommend is you need to kick, not punch. go for his legs and do leg kicks. kick his leg and pull out, and do that multiple times to make him feel pain on his legs. you should not go f or his body. dont hit his neck or face, unless it is really necessary since he can counter you because arms are shorter than legs. you should watch out for a take down. he can charge you hard and slam you on the ground and god know what he will do. he can kick your face or throw punches here and there and you are done due to the size difference. street fight can be very different from UFC. use your elbow too if you can.