Cain Velasquez shocked the world last Friday by turning up on Friday Night SmackDown - and now he's officially a WWE superstar.The former UFC heavyweight champion of the world confronted his former enemy Brock Lesnar at the end of the blue brand's first show on FOX in Los Angeles, and he was accompanied by Rey Mysterio.The Master of the 619 gave more context to Velasquez's surprise appearance on Raw this week, by saying Cain is the 'godfather' of his son Dominick, who was viciously assaulted by Lesnar.To some though it wasn't a surprise. Earlier in the week Dave Meltzer had stated Velasquez was going to be brought in and be used as part of the Mysterio and Lesnar storyline, and lo and behold that's what happened.When he appeared on SmackDown though, he hadn't actually signed a deal with the company, leaving them vulnerable to another promotion - like AEW - stealing him from under their noses.

After all, Cain did tag with Cody Rhodes in his first ever wrestling match this year, but Vince McMahon must have been pretty confident about securing him, and that is what was announced today.

ESPN's Marc Raimondi confirmed earlier this evening that Velasquez had signed on the dotted line with WWE, and it's not just a one-and-done match with Lesnar at Crown Jewel - he's penned a multi-year contract.

And subsequently that has brought an end to his MMA career, with Cain notifying the UFC of his retirement and he has dropped out of the USADA testing pool, and consequentially - the heavyweight rankings.

Velasquez tore ligaments in his knee in his last fight - a quick KO loss to Francis Ngannou back in February, but he's still been able to wrestle two matches since then.

His third will come on October 31 in Riyadh, Saudi Arabia against Lesnar, but you have to wonder how long his knee will hold up for before he really does need to go under the knife.

WWE have swooped though before anyone else to lock down the Californian, and he could be a major asset for years to come.