Conor McGregor Trash Talks Jake Paul After Katie Taylor's Victory over Amanda Serrano

There were 2 fights connected to the boxing showdown between Katie Taylor and Amanda Serrano Saturday night -- the fight in the ring, and the fight between their supporters, Jake Paul and Conor McGregor.

Katie beat Serrano in a split decision at Madison Square Garden. Conor -- true to form -- who's in Katie's corner, zeroed in on Jake on social media, comparing him to deceased BBC personality Jimmy Savile ... a man who was suspected of sexual abuse.

McGregor wrote, "Who the f*** is this jackass in the pink Jimmy Savile glasses?"

Now what a shock, we say jokingly, Jake responded ... "I'm the one who has done more for fighters than you ever have; the one who has won five fights in the past two years while you have lost five."

Jake wasn't done ... "The one who isn’t owned by Dana White, the one who made the fight you just watched happen, the one who got your hero Katie Taylor paid, that’s who."

McGregor's comeback ... a pic of Savile sporting pink glasses similar to the ones Jake wore at the Garden.

The 2 have been trash talking for months now, and ya gotta think a fight would line both their pockets with millions and millions of bucks. Problem for Conor -- Jake is 6'1" and 210 lbs, while Conor's 5'8", and now weighs about 175 lbs.