Report: Brock Lesnar retires from MMA

Brock Lesnar's return to the UFC lasted one fight.

The 39-year-old former heavyweight champion told company officials that he is retiring from MMA competition for a second time, according to MMA Fighting's Marc Raimondi, citing a UFC spokesperson.

Lesnar came back from a four-and-a-half-year break from MMA to defeat Mark Hunt by unanimous decision at UFC 200 last July. That win became a no-contest when Lesnar tested positive for banned substances in both his in- and out-of-competition drug tests. He received a one-year suspension dating back to the Hunt bout and will have to serve out the remainder of that punishment should he return to fighting.

USADA spokesperson Ryan Madden confirmed that Lesnar has been removed from the drug-testing pool, and Lesnar's profile is no longer listed among the active heavyweights on the UFC website.

As it stands, Lesnar retires with a 5-3 record with one no-contest. He transitioned to MMA after an enormously successful run with the WWE, capturing UFC gold in just his fourth professional fight with a second-round TKO of the legendary Randy Couture.

Lesnar went on to successfully defend his UFC belt twice against Frank Mir and Shane Carwin before losing it to Cain Velasquez. A subsequent loss to Alistair Overeem sent Lesnar into his first retirement, which led to another lucrative stint in the WWE.

A former Division-I wrestling champion, Lesnar was a sensation in his brief MMA career, becoming one of the biggest draws in UFC history despite competing just eight times inside the Octagon.