A new era in the Middleweight division has begun. Israel Adesanya knocked out Robert "The Reaper" Whittaker in the second round, becoming the undisputed UFC Middleweight Champion.The celebrations have begun and Israel Adesanya vs Paulo Costa is the next fight for the Middleweight Championship, as all signs have pointed to.The main card wasn't the most hyped one this year, but it still delivered, opening and closing with fantastic knockouts. In the main card opener, Yorgan de Castro knocked out Justin Tafa. Dhiego Lima extended his win-streak to three matches following a surprising split decision victory over Luke Jumeau.Tai Tuivasa didn't have the homecoming he wanted as Sergey Spivak submitted him in the second round. Meanwhile, Dan Hooker put on one of his best performances to date as he beat former title challenger Al Iaquinta by unaninmous decision, calling out Dustin Poirier for a fight in New Zealand next year.Here is what the MMA Twitterverse and fighters had to say about the main card!Israel Adesanya vs. "Over inflated balloon animal, Ricky Martin look alike" Paulo Costa. Inject this into my veins.— Brett Okamoto (@bokamotoESPN) October 6, 2019Well there’s that. Izzy showed up BIG. Congrats @stylebender see you around my man.— #OnAmission4Gold (@KelvinGastelum) October 6, 2019In just 20 months, Israel Adesanya has gone from making his UFC debut to becoming the 185lbs Champ. During this run he has defeated:-Rob Wilkinson-Marvin Vettori-Brad Tavares-Derek Brunson-Anderson Silva-Robert WhittakerMission complete. Well done, @stylebender. #UFC243— Chamatkar Sandhu (@SandhuMMA) October 6, 2019People were impressed with Dan Hooker's unanimous decision victory over Al Iaquinta. He called out Dustin Poirier and while many might think that it's a step too high for him, it's still a very interesting match-up to make, especially given that Justin Gaethje is sitting out for the winner of Khabib Nurmagomedov and Tony Ferguson.Dan Hooker is the dark horse of the lightweight division. What a great win over my guy Al Iaquinta. The Barboza loss was a hiccup, but I think Hooker will be challenging for a title in the near future. Watch out Dustin Poirier! #UFC243— Darren #IaquintaNation (@RagingMacs) October 6, 2019Dan Hooker with a phenomenal performance. He wins via UD over AL Iaquinta.Afterwards, Hooker calls out Dustin Poirier. "Dustin Poirier, I'm going to smash your face in. Meet me in New Zealand, 2020, and I'm going to end you!"— Ariel Helwani (@arielhelwani) October 6, 2019The Tai Tuivasa hype train unfortunately came crashing to a halt after losing by technical submission. Tuivasa lost a friend last week due to mental health-related reasons and it's unfortunate that he didn't pick up the win.I cant help but feel bad for Tai Tuivasa after going from being undefeated to being 3-3 in the UFC with 3 losses in a row 😥 #UFC243— Uptown Funk (@Uptown_MMA) October 6, 2019The Tai Tuivasa hype train has officially been derailed for good. #UFCMelbourne pic.twitter.com/NSsryF5n75— 👉 𝙈𝙈𝘼 𝙎𝙋𝙊𝙏𝙇𝙄𝙂𝙃𝙏 👈 (@Spotlight_MMA) October 6, 2019Dhiego Lima extended his win-fight to three matches in a row as he won by Split decision. The decision was a controversy as it was clearly a uninanimous decision for Lima.How on earth did one judge not have Dhiego Lima winning #UFC243 pic.twitter.com/z7UpgZ5tk8— Andy Dawson (@A_Dawsonn) October 6, 2019Dhiego Lima: "This is the most confident I’ve ever been before they announce a decision. Then they go and say 29-28 Luke and I’m like ‘Come on!’ I’ve got to start finishing more fights. It sucked. I thought I clearly won."#UFC243— Damon Martin (@DamonMartin) October 6, 2019Yorgan De Castro vs Justin Tafa proved to be the perfect opener as we saw the former land the perfect hook to secure a first-round knockout.Replay of Yorgan De Castro's KO at #UFC243: pic.twitter.com/CX9ak5REOE— MMAFighting.com (@MMAFighting) October 6, 2019Oh God… Yorgan de Castro just gave Justin Tafa one-way ticket to the shadow realm #UFC243— José Youngs (@JoseYoungs) October 6, 2019Here are a few more reactions to the stunning main event victory of Israel Adesanya!And then there were 2 UFC UNDISPUTED CHAMPIONS 🇳🇬🇳🇬✊🏾✊🏾Congrats my brother @stylebender #wenodeycarrylast pic.twitter.com/BskzzMTZZ3— KAMARU USMAN (@USMAN84kg) October 6, 2019The Adesanya fam celebrates @stylebender's coronation at #UFC243 pic.twitter.com/jxhVty3Rn8— ESPN MMA (@espnmma) October 6, 2019They called him skinny, booed him, well heres how it ended, Never look down on anyone....Thanks for making me some money Izzy, I never doubted #UFC243 #Adesanya #Izzy pic.twitter.com/MnzwP45V8b— Mercy.Lambo🇳🇬 (@Jamesver_) October 6, 2019Follow Sportskeeda Wrestling and Sportskeeda MMA on Twitter for all the latest news. Do not miss out!