Jon Jones made it look easy as he submitted Cyril Gane in just over two minutes to secure the vacant heavyweight championship in the UFC 285 main event.

Jones, who came into the contest with a 27-1 record and was already considered one of the greatest fighters in UFC history, added another notch to his resume as he added the heavyweight belt to his 15 light heavyweight title fight victories.

Against Gane, Jones was faced with the first size disadvantage of his career, although he did come in as the slightly heavier fighter at 249lbs to Gane's 248lbs.

But the battle was always going to be about whether Gane could prevent the takedowns and stay on his feet, and that question was answered a minute into the first round.

After the first kick of the fight nailed Jones square in the cup, causing a brief delay, the 35-year-old Hall of Fame inductee came out of the restart and immediately secured a takedown.

Gane tried to do the right things, keeping his back up against the cage to aid his chances of getting back to his feet, but Jones stayed patient and waited for his opening.

After initially threatening a guillotine choke that he could not lock up properly, Jones clearly identified a hole in the big Frenchman's defence, repositioning and attacking with the same guillotine choke while Gane was seated upright against the cage.

Once it was on properly, the tap came almost immediately, with the fight stopped at 2:04 into the first round.

But while one legend climbed further into the pantheon of the greatest fighters to ever walk the planet, another suffered a shocking defeat, as flyweight champion Valentina Shevchenko was submitted by Alexa Grasso in the fourth round.

An overwhelming favourite, Shevchenko came into the contest on a nine-fight winning streak dating back to 2018, but after surviving a close split decision her last time out against Talia Santos, she again looked a far cry from her dominant best.

Grasso's boxing in the first round illustrated that she may have the edge on the feet, forcing the well-rounded champion to pivot her strategy and spend the second and third rounds largely in top position after a series of takedowns.

The fourth round was neck-and-neck, until Shevchenko threw a spinning back kick, exposing her back and allowing Grasso to latch on, sink her hooks in and work the rear naked choke.

It was not tight enough to finish initially, but the challenger remained calm and slowly adjusted her grip until the champion was forced to tap for the first time in her career.

With the stunning upset, Grasso became the first Mexican woman to ever win a UFC title, and she has a chance to potentially main event a pay per view when it comes time for the inevitable rematch.

Jiri Prochazka dethroned Glover Teixeira to claim the light-heavyweight title at UFC 275 in a fight the new champion described as "a true war".

The 29-year-old was trailing Teixeira on two of the judges' scorecards, with the other judge having it level, when he won with a rear-naked choke submission in the fifth round.

That brought an end to a gruelling bout in Singapore, with Prochazka coming through nearly five rounds of relentless punishment from his 42-year-old opponent.

"It's amazing and I'm glad. It was a true war. Glover is a true warrior, and I like that," Prochazka, UFC's first Czech champion, said in his post-fight interview.

"I never thought... that's why it's good to not be thinking, you are in the middle of the fight.

"Next time I will be better. I was ready to end the fight whenever today, whether in the first or fifth round, it doesn’t matter, and it doesn't matter which technique."

Teixeira became the oldest first-time champion in UFC history when defeating Jan Blachowicz last October and was 30 seconds away from retaining his title against Prochazka.

Despite turning 43 in four months' time, Teixeira has no intention of calling time on his career following Saturday's loss.

"I gave my all out there, no excuses," he said. "His body shots took my gas away, I was gassed out to be honest. But I'm going to keep going."

Valentina Shevchenko defeated Taila Santos by split decision in the women's flyweight fight, meanwhile, in what was her seventh successful title defence.

"I want to keep going, I want to keep improving," Shevchenko said. "I want to keep fighting no matter who – bantamweight, flyweight, I am here. Bring it on."