Hey guys! New poster here. I am looking for some advice, can anyone offer any pointers on:

-How to Box against an opponent who wants to clinch, excessively, &wrestle you to the ropes, push you down, etc. If the referee isn't offering any kind of relief, as a fighter, what can you do to combat this type of opponent? I attend many small shows and commonly see better boxers being drug into a sloppy, ugly match, by a less polished, mauling kind of fighter, who only seems to want to wrestle, and score single blows in the clinch, rabbit punch, lean on &push his opponent to the canvas. My brother is a young boxer and has encountered this several times, &it has troubled him. I'm trying to find some sound advice on this to offer.
Thank you all for your time!
Regards