Paulo Costa made a successful return to the UFC Octagon following a lengthy spell of inactivity through injury - but it was bitter rival Luke Rockhold who stole the show.

Rockhold's pursuit of the light heavyweight title ended in failure in 2019 when he suffered a first-round KO loss to Jan Blachowicz at UFC 239.

The former UFC middleweight champion's first fight since that disappointing night in Las Vegas saw him lock horns with Costa in the co-main event of UFC 278: Kamaru Usman vs Leon Edwards II.

Rockhold was hoping to use the Brazilian, whom he traded verbal barbs with during the build-up to the fight, as a launching pad for a title run at the current champion Israel Adesanya.

READ MORE: UFC 278 results: Leon Edwards stuns Kamaru Usman, Costa beats Rockhold, Aldo loses

However, things didn't go to plan for the 37-year-old as he suffered a unanimous decision loss in front of a sold-out crowd at the Vivint Arena in Salt Lake City.

But he still managed to put on a good show regardless despite visibly gassing during the latter stages of the fight.

As expected Costa came charging out of the blocks, aiming a vicious lead head kick at his opponent's jaw.

WATCH: Luke Rockhold's gangster move against Paulo Costa goes viral as he hints at retirement

Check out the video below...

A second kick followed moments later before he started throwing some punches, which dropped the unsuspecting Rockhold towards the end of that round.

But despite there being some obvious questions about the strength of his chin it seemed to hold up for the most part as he upped the offensive.

Rockhold didn't seem to care too much about engaging with Costa in the stand-up, although he was understandably wary of the Brazilian's power.

Costa soon became wary of stoically walking forward with reckless abandon as each time he did he ended up eating some hard counter shots for his troubles.

On one occasion Rockhold screamed: "F*** you!" at him in frustration before clocking him right in the face which forced him to take a backward step. The clip was posted by Barstool Sports which you can see for yourself in the video above.

Luke Rockhold and Paulo Costa trash talk

The third and final round saw the pair swing for the fences, much to the delight of the pro-American crowd.

Perhaps sensing the moment slipping away from him, Rockhold knew he needed a takedown to try and sway the judges.

And he duly shot in for one, spending a large chunk of the third round on top of his bloodied opponent.

However, it had little effect on the judges' scorecards as they awarded Costa a unanimous decision victory, with all three scoring the fight 30-27, 30-27 and 30-27 in his favour.

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Afterwards Rockhold indicated he will likely hang up his gloves after 22 professional fights, declaring he has become too old to compete in the sport.

He told Joe Rogan: “I’m been through so much the last three years.

“I f***ing… thank you, fighting. Thank you, UFC. Thank you, Joe.

"I f***ing can’t do this s*** any more. I gave it my all. I just didn’t… I’m f***ing old.”