Jon Jones employed a guillotine choke to submit Ciryl Gane in the first round of the UFC 285 main event on Saturday night in Las Vegas, claiming the vacant heavyweight title.
Jones becomes the eighth fighter in UFC history to win titles in two divisions.
Also, Alexa Grasso submitted Valentina Shevchenko in the fourth round in a stunning upset to become the new women's flyweight champion.
Jones, who vacated the 205-pound title to move up to heavyweight, submitted Gane at 2.04 of the opening round for his first submission in 11 years.
"I've been working for this for a long time," Jones said afterward. "A lot of people thought I wasn't coming back. I've been faithful to my goal. I've been faithful to the mission. There were days I didn't want to train and I was always there."
Jones had not fought since February 2020.
Grasso submitted Shevchenko at 4.34 of the fourth round with a rear naked choke. Shevchenko had successfully defended her title seven times.
"Please punch me, I feel like I'm dreaming," Grasso said. "I've been dreaming for this moment for so long."
Sanju Samson has struggled for form since being named Player of the Tournament at the T20 World Cup but the wicketkeeper-batter looked more like his old self on Saturday with an unbeaten 115 off 56 balls in Chennai's 23-run win over Delhi Capitals.
Rory McIlroy discovered again on Saturday that nothing at the Masters is secure as the defending champion's overnight six-shot advantage vanished in the Georgia heat and Cameron Young charged into a share of the lead at 11-under after the third round.
Belgium knocked out 18-times champions the US to qualify for the Billie Jean King Cup Finals on Saturday, as Britain, Italy, Kazakhstan, Spain, Ukraine and Czech Republic also secured places in the season-ending team event alongside hosts China.
Liverpool's teenage winger Rio Ngumoha has become the club's youngest player to score a Premier League goal at Anfield on Saturday before Mohamed Salah struck four minutes later in a 2-0 win over Fulham that boosted their quest for a top-five finish.
Britain's former heavyweight world champion, Tyson Fury, has outclassed Russia's Arslanbek Makhmudov en route to a comprehensive points win on Saturday and then called for a showdown with compatriot Anthony Joshua.