Roman Reigns Cops $450k Watch, Diamond Chains During WrestleMania Weekend

Roman Reigns didn't get a win in his triple threat match at WrestleMania ... but he certainly didn't leave Vegas empty-handed -- thanks to his new luxury watch and diamond chains!!

TMZ Sports is told ... Eric the Jeweler from Mavani and Co. in New York flew out to Sin City to catch all the WWE action over the weekend -- and had the Tribal Chief's newest accessories in tow.

Roman and Eric linked up during the festivities ... and the latter handed over a 44mm Black Ceramic Openwork Audemars Piguet, which is rare and valued at around $450,000.

But the expensive timepiece wasn't the only item on Roman's order -- he also received two black diamond tennis chains with 55 carats.

We're told Roman just wanted to treat himself ... and that he did. While he's not the most giddy person in the world, we can still tell he was happy with the final product.

It was a wild Saturday in the ring for him -- with longtime partner/WWE legend Paul Heyman electing to support Seth Rollins over him or CM Punk.