Deontay Wilder has criticised Anthony Joshua for a lack of confidence after the Briton suggested he may not be ready for a heavyweight unification bout until 2019 or 2020.
Wilder is the WBC champion in the top weight class and is poised to defend that belt against Bermane Stiverne next month after his previous scheduled fight with Luis Ortiz was cancelled due to the Cuban failing a drugs test.
IBF, WBA and IBO champion Joshua takes on Kubrat Pulev on October 28 but has hinted a fight with Wilder may be some way off.
Responding to those remarks, Wilder - who is 38-0 with all but one of those wins by knockout - said: "What other heavyweight does what I do? What other heavyweight has the power like me, I don't have to punch in bunches, one punch goodnight.
"I am the most feared, the baddest, the hard-hitting heavyweight and please tell your favourite fighter to come and see me.
"My doors are open, my jungle is free, please travel down this path with me and see who comes out on top and I promise you this boy right here - this black American from Alabama - will come out on top each and every time, I'll put my money on that.
"In this boxing thing you have to have competition... you have to sound like you're the best, you can never sound like you need more time for another champion to prepare to put yourself in a better position AJ! That doesn't sound too confident."
Joshua is seen as the king of the heavyweight division following his thrilling 11th-round stoppage of Wladimir Klitschko in April.
But Wilder feels he deserves the same respect, adding: "Don't be fooled, do your research when you come to criticise me.
"The thing about fighters from other countries, their people are behind them, they support them no matter what, a lot of you won't want to hear that but that's okay, do your research.
"Make sure you get your information right about me, make sure you do your research so when you write your blogs, when you do your videos, when you go and tell the stories about Deontay Wilder, you get it correct."
|Marseille still underdogs against Salzburg, says Payet|
|Wenger rues ´worst possible´ goal from Griezmann|
|Griezmann: Oblak is the best goalkeeper in the world|
|Besiktas refuse to complete abandoned Fenerbahce semi-final|
|´Better mentality´ key to improved Nadal showing|
|Barba injury threatens to overshadow Saints´ rout of Salford|
|Marseille 2 Red Bull Salzburg 0: Thauvin, N´Jie earn semi-final advantage|
|Arsenal 1 Atletico Madrid 1: Griezmann smuggles vital away goal for 10-man Atleti|
|Woods to return at Wells Fargo Championship|
|Hamilton: Respect between Vettel and I has grown|
|Mourinho: Chelsea sold Salah, not me|
|Vrsaljko and Simeone sent off in dramatic start to Arsenal v Atletico|
|Kerber and Muguruza retire from Stuttgart Open|
|Khan planning major Wembley refurbishment if bid is accepted|
|Panthers respond to alleged Jerry Richardson victim´s expose|
|Cazorla trains at Emirates after injury agony|
|Kings XI crumble as Rashid spins Sunrisers to success|
|Costa makes Atleti bench as Ozil returns for Arsenal|
|Wozniacki´s comeback edges out Errani|
|Dimitrov fends off match points as Nadal cruises through|
|Two men remanded in custody over Liverpool fan attack|
|Sweet 16 for Nadal in swatting aside Garcia-Lopez|
|Liverpool book ´extraordinary´ Rome meeting to plan fan safety|
|Burnley confirm Arfield, Marney departures|
|Under-fire Montella acknowledges Sevilla in ´very bad´ form|
|Wilder jibe motivated Fury to embark on road to recovery|
|Jerome Boateng to ´fight´ for World Cup place after season-ending injury|
|Luckless Roland-Jones out for the season|
|Ricciardo denies Ferrari rumours|
|Khan won´t relocate England national teams if Wembley bid is accepted|
|Additional World T20 to replace Champions Trophy in 2021|
|Ibrahimovic will not play at the World Cup, says Swedish FA|
|Oates inspires Broncos victory over Rabbitohs|
|FA confirms offer made to buy Wembley Stadium|
|Quarterback-needy teams must drown out noise of NFL´s silly season|
|Betis would welcome Ceballos back with open arms – Joaquin|
|Turkey submits Euro 2024 bid to rival Germany|
|Meyer ´definitely´ leaving Schalke, confirms Heidel|
|Rank outsider Jin leads China Open|
|Buffon apologises for snubbing fans after Napoli defeat|
|Semenya appears unimpressed with IAAF hyperandrogenism rule|
|UEFA charges Bayern Munich over pitch invasion and banner|
|Police charge two over Liverpool fan attack|
|Shields in the dark over England availability|
|Hearn: Wilder´s $50million Joshua offer a PR move|
|Bayern were naive and reckless – Kimmich|
|Salah a nightmare to train against – Alexander-Arnold|
|Ramos: If Iniesta was Andresinho, he would´ve won Ballon d´Or|
|Marlins upset Kershaw, Dodgers to win first series|
|Thunder overturn 25-point deficit to avoid elimination, LeBron buzzer-beater lifts Cavs|
|Guadalajara 1 Toronto 2 (3-3 agg, 4-2 on pens): Mexican hosts win CONCACAF Champions League|
|Hawks, coach Mike Budenholzer part ways|
|Copa Libertadores Review: Palmeiras advance, Nacional claim crucial win|
|WATCH: LeBron James sinks three for buzzer-beating win|
|I´m the best defender in Serie A, says Inter´s Miranda|
|Real Madrid still relying on Bale – Zidane|
|´I don´t f****** want to´ – Harvey refused to talk about bullpen debut|
|Wilder´s camp extends $50m offer for fight with Joshua|
|Ramos: Madrid were expected to win 3-0 but Bayern are difficult|
|Boateng casts doubt over Bayern future|
|Salah a Ballon d´Or contender, says Lovren|
|Muller demands killer mentality from Bayern at Bernabeu|
|Cavs´ Hill ruled out of game five with back spasms|
|Kimmich: Bayern should have beaten Madrid 7-2|
|Brewers´ Thames placed on DL with torn thumb ligament|
|Heynckes: We gave Real Madrid two goals|
|Wenger intends to ´play in Europe again´|
|Madrid suffered in Munich triumph, says Kroos|
|Hitting new heights, but Empire State visit not to Masters champion Reed´s liking|
|Isco injury prompted Asensio introduction – Zidane|