(CNN) Irish mixed martial arts fighter Conor McGregor was victorious in his first UFC match in over 15 months, with a technical knockout win over American opponent Donald "Cowboy" Cerrone in Las Vegas, Nevada. McGregor blitzed Cerrone from the opening bell and won the fight less than a minute into the first round.
McGregor improves his career professional record to 22-4 with 19 knockouts. Cerrone, the UFC's all-time winningest fighter, drops to 36-14 in his professional career.
Conor McGregor returns to the octagon
Conor McGregor celebrates after knocking out Donald Cerrone in their welterweight fight during the UFC 246 event at T-Mobile Arena on Saturday in Las Vegas.
McGregor hits Cerrone during their UFC 246 welterweight mixed martial arts bout.
McGregor lands a knee to the face of Cerrone. McGregor blitzed Cerrone from the opening bell and won the fight less than a minute into the first round.
McGregor celebrates after defeating Cerrone. McGregor improves his career professional record to 22-4 with 19 knockouts.
Cerrone reacts after his TKO loss to McGregor. Cerrone, the UFC's all-time winningest fighter, drops to 36-14 in his professional career.
McGregor is seen with his eyes closed after arriving on the octagon.
McGregor acknowledges the crowd after entering the octagon.
Cerrone heads to the octagon before his welterweight fight against McGregor.
McGregor kicks Cerrone in the face.
A general view of the octagon showing the colors of Ireland during the McGregor-Cerrone UFC 246 event.
McGregor walks away after knocking out Cerrone in their welterweight fight.
McGregor and Cerrone shake hands after their welterweight fight.
Conor McGregor is hugged by Jerry Cerrone, the grandmother of Donald Cerrone, after the bout.
Cerrone has his hands taped.
McGregor has his hands wrapped.
McGregor, left, and Cerrone pose during a ceremonial weigh-in for a UFC 246 welterweight mixed martial arts bout Friday in Las Vegas.
This was McGregor's first time in the octagon since a loss to Khabib Nurmagomedov on October 6, 2018, and a night some thought might never happen. In March of 2019 McGregor tweeted that he planned to retire, then hinted at a future UFC fight the very next week.
There was a post-fight melee between McGregor and Nurmagomedov's camps, which resulted in a six-month suspension for the Irishman and a nine-month suspension for the Russian by the Nevada State Athletic Commission.
McGregor's most recent victory in mixed martial arts came in November 2016 when he won by knockout over Eddie Alvarez.
Despite the long layoff, McGregor is the fourth ranked lightweight in UFC. He is 13th on the pound-for-pound ratings.
Cerrone is ranked fifth among lightweights.
The two fighters, however, competed in a heavier division, as welterweights.