Kubrat Pulev confronted Anthony Joshua before he weighed in for their heavyweight clash - but the Brit vowed to have the last word.
Joshua was preparing to step on the scales when his opponent began the trash talking early on Friday afternoon.
The pair were kept apart before world champion Joshua scaled 240.8lb, almost four pounds lighter than he was last time out against Andy Ruiz Jr.
Pulev had earlier scaled 239.7lb, the lightest he has scaled since his professional debut in 2009.
The pair continued to trade insults after they had faced off as Pulev bids to upset the odds - and Joshua's plan to fight Tyson Fury next year.
The champion said: "That's just how we are, we talk a lot of rubbish; it's just about backing yourself.
"For many years I've been watching boxing and fighters talk a lot of rubbish then they get beaten up.
"I would have clapped him on his jaw but I've got to do it tomorrow. He thinks he's a warrior but I said don't let the guys he's fought gas him up, he's in with a real one now.
"People come in the ring with me and they're confident then after a few rounds their soul gets destroyed and I take them out.
"We're big boys and we punch heavy so the first man who lands will be the last man standing."
Joshua is the odds-on favourite to beat Pulev who has worked his way into the mandatory challenger spot.
The rivals were due to fight in 2017 but a shoulder injured forced the Bulgarian to withdraw.
And earlier this week he said: "I'm ready for this fight, we spend a long time waiting because 2017 I had a problem and that is why I tell my trainer we must go for the win.
"That is why I said let's not fight now (in 2017) because I believed this fight would come again one day and I'm here now, ready to fight good and ready to win."
