Israel Adesanya, the champion, is stunned by Sean Strickland to win the UFC middleweight championship

Polarising After a grueling bout in Sydney, Sean Strickland threw a barrage of hard punches to beat champion Israel Adesanya and win the UFC middleweight championship.

American Strickland upset hot favorite Adesanya in the main event of UFC 293 to capture the 185-pound title by unanimous decision (49-46, 49-46, 49-46) after a five-round brawl.

Strickland repeatedly delivered stinging blows to the head in the packed Qudos Bank Arena, keeping Adesanya on his heels the whole time.

“Never in a million years did I think I would be here,” said Strickland after handing the New Zealander Adesanya her third loss in as many bouts.

“I anticipated feeling a bit broken up when I left. That’s why I’m a bit surprised it didn’t.

It’s the first time I can’t think of anything to say.

When Adesanya’s South African opponent Dricus du Plessis was unable to compete, Strickland, who had previously stirred up controversy with his sexist remarks about putting women back in the kitchen, decided to fight on short notice.

Strickland, who is rated fifth, earned his chance at the championship after defeating Abus Magomedov and Nassourdine Imavov.

The first UFC bout to take place in Sydney since 2017 began with a tense opening exchange between the two competitors.

In an effort to pull off a dramatic upset, the 32-year-old tried to play to his strengths of wrestling and close-range punching.

Late in the first round, after landing a devastating right-hand punch that knocked out Adesanya, he made his move.

Adesanya rebounded in the second round after surviving Strickland’s barrage and used his go-to kicks to devastating effect.

In the third round, Adesanya seemed to be in charge but Strickland connected with a left hook and the battle continued.

In the final seconds, with a shock championship won, Strickland (28-5) was merciless and trash-talked a bloodied Adesanya, a former kickboxer regarded as the star fighter in mixed martial arts.

The two-metre (six foot seven inch) Alexander Volkov, who won the heavyweight match via submission against the Australian Tai Tuivasa, also competed on the main night.

Russian Volkov, who had a five-inch height advantage, proved his favoritism by submitting Tuivasa in the second round through the Ezekiel choke while putting his opponent to the ground with his right arm around the neck.

For the first bout since 2016, 34-year-old Volkov won via submission. “(He took) so many punches and he was still on his legs, this guy is very tough,” Volkov remarked.

In the other heavyweight contest, Justin Tafa of New Zealand stopped American Austen Lane in the first round with a left hook to the jaw.

After lightweight champion Islam Makhachev defeated native Alexander Volkanovski at Perth Arena in February, it was the second UFC event to take place in Australia this year.