In April 2012, Lesnar returned to professional wrestling, rejoining WWE after an eight-year hiatus. Two years later, at WrestleMania XXX, Lesnar defeated The Undertaker to end his undefeated streak at WrestleMania. He achieved world champion status five times after this, having won the WWE (World Heavyweight) Championship in 2014 and 2019 as well as the WWE Universal Championship in 2017, 2018, and 2019. His first reign as Universal Champion was the longest world title reign in WWE since 1988 at 504 days (though recognized as 503 days by WWE), the sixth-longest world championship reign in the promotion's history. In June 2016, at "UFC 199", the UFC advertised Lesnar's return to fight at "UFC 200" even though he was still contracted with WWE. Lesnar defeated his opponent Mark Hunt via unanimous decision. However, after Lesnar was tested positive for clomiphene, a banned substance on the UFC's anti-doping policy, he was suspended from the UFC by the Nevada State Athletic Commission for one year and fined $250,000, and his victory over Hunt was overturned to a no-contest. Lesnar then retired from MMA for the second time in 2017.