Errol Spence Jr: Unified champion says he has "mental edge" over Terence Crawford for undisputed fight

Errol Spence Jr believes he has the "mental edge" over Terence Crawford before their undisputed welterweight fight on Saturday in Las Vegas.

Spence, 31, aims to win his first undisputed championship by capturing Crawford's WBO title.

The fighters and their teams clashed repeatedly at the news conference, with Spence branding Crawford "too emotional" as he argued with hecklers.

"I definitely have the mental edge," Spence told BBC Sport.

"His team [were] heckling me and I just smiled. It comes with the territory. I'm not getting paid to fight them, I'm getting paid to fight him.

"So my attention is to him, not his coach not towards anybody else."

Spence is undefeated in 28 fights and holds the WBC, WBA (Super) and IBF titles. He is just four years Crawford's junior and visibly bristled when his opponent called him "kid".

It was the only time in a news conference repeatedly interrupted by heckling from both fighter's camps Spence appeared irked.

• 'This is the Terence 'Bud' Crawford era'

• Bunce column: A brilliant fight, but Spence-Crawford lacks stardust

• LISTEN: 5 Live Boxing: Bridges, Coldwell & Spence v Crawford

After the news conference, he said: "I'm not a kid. I'm a grown man."

While Crawford eventually lost his cool with the hecklers, Spence insisted the exchanges were to be expected so close to the fight.

"I wasn't expecting all that. With his coach and my coach getting into it and Terence getting into it with somebody in the crowd. But you know that's what happens," he said.

"Tensions flying right now because the weigh-in's tomorrow, two days to the fight.

"We're two alpha teams basically ramming heads with each other right now. That's what you're going to get, especially this close to a fight."