Tony Ferguson, left, falls backward after taking a punch from Justin Gaethje during a UFC 249 mixed martial arts bout, May 10, 2020, in Jacksonville, Florida, United States. (JOHN RAOUX / AP)

NEW YORK - The UFC returned on Saturday for the first time since the COVID-19 outbreak first began shutting down sporting events around the world.

With Tony Ferguson still standing and uneasy on his feet, referee Herb Dean stopped the fight following a huge blow and a flurry of head shots from challenger Justin Gaethje

The event, UFC 249, had initially been slated for April 18.

The mixed martial arts organization had been put on hold for two months following UFC Fight Night: Lee vs. Oliveira in Brasilia, Brazil, on March 14.

After months of wrangling over potential locations and dates, UFC President Dana White settled on VyStar Veterans Memorial Arena in Jacksonville, Florida.

Before White found Jacksonville as the willing host, other locations had been considered, including an undisclosed private "fight island", the state of Nevada and original host New York City.

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In addition to location, the fight card dramatically changed too. The headline event had initially been Tony Ferguson versus UFC Lightweight Champion Khabib Nurmagomedov. However, the outbreak meant that the Russian Dagestani champion Khabib was marooned in Dagestan due to travel restrictions ordered by the local Russian and US governments.

Number four ranked lightweight Justin Gaethje replaced Khabib at the top of the card for the interim UFC Lightweight belt.

Gaethje, the heavy underdog, started the fight well with his solid orthodox style against Ferguson's awkward but deadly strikes in the first two rounds before Ferguson landed a knockdown uppercut at the end of the second round.

Henry Cejudo, right, punches Dominick Cruz during a UFC 249 mixed martial arts bout, May 9, 2020, in Jacksonville, Florida, United States. (JOHN RAOUX / AP)

Yet, despite the knockdown, Gaethje kept up the pressure and continued to land on Ferguson throughout round three.

Ferguson, who entered the fight on a 12 fight undefeated streak, never settled into the fight thanks to Gaethje's superb counter-striking and defense.

As well as hard-hitting counterpunches, Gaethje also used leg kicks to slow Ferguson down.

By the fifth and final round, Gaethje was landing on Ferguson at will. With Ferguson still standing and uneasy on his feet, referee Herb Dean stopped the fight following a huge blow and a flurry of head shots.

Down the card, the Henry Cejudo and Dominic Cruz clash, which had remained untouched from the first card, saw the two-weight champion and Olympic Gold medallist Cejudo win with a second-round stoppage after a series of unanswered blows to Cruz's head.

Following the fight, the USA gold medallist shocked the onlooking UFC President White by announcing his retirement from the sport at 33 and declaring himself the greatest combat sports athlete of all time.

Supporting the Cejudo/Cruz clash was the heavyweight battle between the two 190 cm monsters Francis Ngannou of Cameroon and Suriname's Jairzinho Rozenstruik that ended with a colossal KO for the Cameroonian after just 20 seconds.

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The bout between Ngannou and Rozenstruik was set to be its own fight night event but had to be folded into the UFC 249 card due to COVID-19.

Inside the arena, while the seats remained empty and void of spectators around the octagon, each fighter had a full complement of coaches and cutmen. The UFC also had an entire production team, including long time announcer Bruce Buffer and the usual commentary team ringside, albeit with all non-speaking roles in the production team always required to wear face masks.