Fedor Emelianenko took down Quinton "Rampage" Jackson via first-round knockout in the Bellator 237 main event on Saturday (Sunday in Japan Standard Time).

Bellator and Rizin Japan co-produced the fight card, which took place at Saitama Super Arena in Saitama, Japan.

Emelianenko took charge of the fight early with a flurry of punches to open the first round:

Eventually, a quick right hand to Jackson ended the bout at 2:44 of the opening frame.

After the win, Emelianenko told fans he may retire:

Emelianenko and Jackson are past their primes on the north side of 40 years old, but the two fighters were among some of MMA's biggest names in past years.

Both have stellar resumes. The 43-year-old Emelianenko posted a 38-6 professional record with one no-contest before Saturday, and he's also won PRIDE and WAMMA heavyweight championships.

Emelianenko nearly added a Bellator heavyweight title as well, but Ryan Bader defeated him via first-round knockout in the weight class' World Grand Prix Final on Jan. 26.

Emelianenko is also in the middle of a successful second act in his MMA career. The Russian retired in 2012 but came back three-and-a-half years later, winning his first two fights.

The Russian then began competing for Bellator, where he's 3-2.

As for Jackson, the 41-year-old has beaten some of the sport's biggest all-time names, including Chuck Liddell, Dan Henderson and Matt Hamill.

His win over Liddell gave him the UFC light heavyweight belt in May 2007 thanks to a first-round TKO. Jackson successfully defended his title via unanimous decision over Henderson four months later but lost a championship bout to Forrest Griffin in July 2008.

The Griffin-Jackson matchup, which ended in a unanimous decision, was voted as UFC's Fight of the Year.

Jackson won four of his next five fights after the Griffin bout but lost three straight afterward. He signed with Bellator in 2013 and has found success, going 5-3.

Jackson had not fought since September 2018, but that bout resulted in a second-round TKO win over Wanderlei Silva.

Emelianenko entered the fight as a slight -135 favorite ($135 bet to win $100), per Caesars Sportsbook.