Cain Velasquez's rise to the top of the mixed martial arts world was meteoric. In less than three years, he went from Octagon newbie to UFC heavyweight champion.The man he defeated to become champion? Brock Lesnar. Fast forward several years and the two are now set for a rematch, albeit under vastly different circumstances. Following a few injury-plagued years in the cage, Velasquez has opted to join Lesnar in the WWE sphere.WWE officials last Friday made Velasquez's signing official, announcing that he would face WWE champion Brock Lesnar at the pro wrestling promotion's Crown Jewel event on Oct. 31 in Saudi Arabia. When the two met in the Octagon, it took Velasquez little more than four minutes to pound out Lesnar to capture UFC gold. Lesnar will now get the opportunity to even the score in a world in which he is vastly more experienced than Velasquez.Over the course of 13 years, Velasquez amassed a 14-3 record in mixed martial arts, which included two stints as the UFC heavyweight champion.* * *TRENDING Cain Velasquez and Brock Lesnar to rematch in WWE* * *With the WWE match-up becoming official, Velasquez on Monday issued a farewell statement to UFC officials and fans, as he embarks on his WWE journey."To the UFC, my family, friends, and all the fans, thank you for the past 11 years. Thank you to all my coaches, teammates and agents. I am so blessed to have been able to have a career doing something I absolutely love. I knew from the time I was a junior in college I wanted to be a fighter and after graduating from college, I set off on my journey of becoming a fighter with the goal of being UFC Heavyweight champion. There are few people in this world that can say they have achieved what I have, and I am forever grateful for the opportunities and position I held being a part of the UFC. With my official retirement from the UFC, it’s time for the next chapter."A year ago, when I went to my first WWE show, I fell back in love with a sport that I had watched and participated in since I was a child. From that moment, I have been doing a crash course on all things that relate to pro wrestling. I’ve been training at different gyms, going to shows and watching more matches (than) I would like to admit, but I can honestly say I eat, sleep and breathe wrestling now. The contract is signed and I’m on my way to my next goal which is Universal Champion."WWE Universe, thank you for welcoming me with open arms."https://www.instagram.com/p/B3m6QoigYUe/