How to handle a friend that’s tough to discuss with?

I have a fairly close friend who tends to not share their opinion much, but when they do give a piece of their mind it’s quite a storm. It usually happens online more often than in person, sometime I would bring up a topic as a discussion, and they would quickly turn it into an argument, as if it was something to be won or loss as they’re a very competitive person. And when it turns into a full blown argument it always feels like I’m being insulted and degraded and just generally feeling like I’m being pulled down to that level, I’d rather not have just regular conversations turn this way but it just happen so often, how do I handle this?