Fans gave mixed reactions as Christian Leroy Duncan defeated Eryk Anders with a brutal first-round knockout in the main card opening bout of UFC Vegas 109.After a few initial exchanges, Duncan delivered hard inside leg kicks. He then charged forward, executing a spinning back elbow that caught Anders off guard and caused him to wobble.Duncan aggressively sought the finish as Anders backed up against the fence. A couple of powerful punches on the chin sat Anders down. The referee waved off the fight as Duncan continued to throw punches and Anders failed to respond or defend himself.The UFC posted the video of the stoppage on X.Check out the moments after Christian Leroy Duncan's knockout of Eryk Anders below:Fans took to the comments section and shared their thoughts on the finish. Some praised Duncan's technique and the set-up for the elbow:"Double tapped, great timing."Another fan commented:"The way he set that spin was amazing."Conversely, a few criticized Duncan for committing fouls during the fight, such as eye pokes and groin shots:One fan chimed in:"He got eye poked, kicked in the nuts, and knocked out in a round. Feel for him, such bad luck."Another fan wrote:"Eye poke & nut shot to lead up to it. Cheating scum."Check out more fan reactions below:Fan reactions [Screenshots courtesy: @ufc on X]Duncan has now won two consecutive bouts since suffering a unanimous decision defeat against Gregory Rodriguez at UFC 304 in July last year. The fight also marked the first knockout loss of Anders' UFC career in nearly seven years. His last knockout defeat was against Thiago Santos in September 2018.Anders has one fight remaining on his UFC contract and has announced his intention to retire from professional MMA competition after his next contest. In an interview with MMA Junkie, Anders expressed the desire to compete at Noche UFC 2025 in September or at the UFC's November pay-per-view, which typically takes place at the iconic Madison Square Garden.