Holly Holm failed to impress despite beating Raquel Pennington by unanimous decision as Conor McGregor stole the show with a sensational 40 second KO of Donald Cerrone at UFC 246.

In a cagey opening round, Holm looked to physically impose herself over her opponent as she tried but ultimately failed to inflict damage on Pennington, albeit while winning the five minutes.

And it was much of the same in the second round as Holm continued to use her power in the clinch to get the better of the action.

The pattern of the fight left fans in the arena frustrated, but the 38-year-old from New Mexico showed no sign of trying to turn the bout into a dogfight in the latter stages despite boos ringing around the stadium.

Inside the last couple of minutes, Holm put together the best combination of the fight as she hit Pennington with one of the few clean punches of the contest.

But it was the clinch which the UFC legend used to secure an ugly win, although she resorted to a muted celebration after the final bell once she realised the crowd were unimpressed.

Speaking about her performance, she said: “It's another victory but I wanted to do a lot better tonight. The whole time I was thinking ' I need to get better strikes in'

"I really feel I can be the champion again but I did not show as much as I wanted to tonight”.

The performance of the night undoubtedly came in the main event where McGregor scored a breathtaking TKO victory inside the first minute over Donald Cerrone in Las Vegas.

After busting Cowboy's nose with a succession of shoulder hits, the Irish fan favourite landed with a perfectly timed head kick before pummelling his opponent to the canvas.

The referee stepped in to give McGregor a record-breaking stoppage and announce his return to the UFC picture after more than a year out of the game.

“It feels very good, I made history tonight," said McGregor. "I set another record, the first man to ever score knockouts in three weight divisions. I am very happy and very proud.

“I like this weight division. I am unscathed and in shape but I still don't think I am back where I was.

“I am going to party and spend time with my family but then I will be back in the gym and ANYONE can get it next!”