Oklahoma City Thunder wing Hamidou Diallo took home the trophy as this year's Slam Dunk Contest winner. He's already calling people out as the reigning champion. The first person in his cross-hairs? Zion Williamson.

Hamidou Diallo and Zion Williamson faced off in 2016 at the Under Armor Elite 24 Dunk Contest.

While both put together strong showings, it was Williamson who came out on top that year. Now that Diallo has an NBA dunk contest win under his belt though, he's ready for the rematch.

Diallo is in his rookie year with the Thunder and playing sparingly. Due to that, he doesn't exactly have big numbers, but the athleticism and potential are clear.

Williamson, on the other hand, is in his Freshman year at Duke. He's taken the basketball world by storm and is a virtual lock for the first overall pick come the 2019 NBA draft.

The 6'7″ forward is averaging 22 points and 9.3 rebounds, while adding 2.0 blocks and 2.3 steals per game as well. With his incredible skill set and athleticism, if Williamson wants to be in the dunk contest next year, no one's going to say no.

Due to that, there's a pretty easy set up for this matchup. Diallo is the reigning champ and Williamson will be the rookie everyone's talking about. Add in the fact that they both have great track records in dunk contests and this would be a rematch and you have all the makings of an absolute fire showdown.

Not to overshadow Diallo, because he deserves a lot of props for his 2019 showing. That dunk over Shaquille O'Neal plus a callback to Vince Carter deserved something higher than a 50.

With that being said, it's hard not to already look past it and get excited for the prospects of a 2020 contest featuring Zion Williamson. No matter how you feel about him as a prospect, it's impossible to deny his athleticism.

Let's hope this happens because it could be the hype train is already rolling.