The Cork middleweight upset the odds and won the war of attrition to claim, by far, the best win of his career.
O’Sullivan defeated rising American star Antoine Douglas via seventh round stoppage to claim the WBO Inter-Continental title in Montreal at Place Bell.
The fight was the chief support bout for Billy Joe Saunders’s defence of his WBO title against home favourite and former IBF titlist David Lemieux – with the winners of the two fights supposedly being in line to face each other as WBC/WBA/IBF champ Gennady Golovkin looks set to rematch Canelo Alvarez
While that fight may not be immediately next, 33 year O’Sullivan most definitely announced himself on the world scene with a fantastic performance that saw him outlast and outmuscle his touted opponent.
Just over two years on from his loss to Chris Eubank Jr, O’Sullivan had rebuilt in Boston, culminating with a impressive stoppage win over Nick Quigley in the headline fight of a Golden Boy on ESPN card.
Douglas had also rebuilt from his stoppage loss to Avtandil Khurtsidze in March 2016, rattling off three stoppage wins and linking up with Golden Boy – tonight being his first fight of this partnership.
It was fireworks throughout, with Douglas starting the sharper, but being worn out by O’Sullivan who brought an end to proceedings in the seventh of ten scheduled rounds.
Douglas began targeting the body as O’Sullivan marched forward relentlessly. The American was peppering Spike with shots, but the Mahon man was able to make his way inside to land some heavy shots and set a quick pace.
Douglas had a better second, looking sharper and landing lots, but O’Sullivan remained on his chest throughout.
O’Sullivan was momentarily staggered by a left hook at the start of the third, but tore straight back into Douglas. The Virginian was landing the greater number of quality shots – but was being made to work hard by the come-forward O’Sullivan whose output had dropped but was hitting home with his fair share of thudding body blows.
A much better fourth from O’Sullivan saw the Celtic Warriors man land his best punch of the fight, a huge left hook, which looked to invigorate Spike and start a slight slowing of Douglas.
The Spike train continued to roll into the fifth as the Munster man began to bring his right backhand into play, finishing the round extremely strong.
The war of attrition resumed in the sixth, with O’Sullivan bulling through Douglas at the start, before a final spurt from the 25 year old in the closing stages.
The end then came in the seventh, with the two trading hooks at the start before O’Sullivan made his breakthrough, bullying Douglas to the ropes and landing clubbing, heavy shots that sent the favourite down. Douglas rose on unsteady legs, but was in no position – and had no desire – to continue and the fight was waved off.
A 2/1 underdog beforehand, O’Sullivan improved to 27(19)-2(1), and will be aiming for huge fights in the new year. A shell-shocked Douglas drops to 22(16)-2(2)