Tony Ferguson loses to Bobby Green via arm triangle at UFC 291.
This marks Ferguson's sixth straight defeat and fourth consecutive finish loss.
Bobby Green ends his three-fight skid with the victory.
Ferguson once held the longest win streak in UFC's lightweight division.
His 2013-2019 run included 12 straight wins with nine finishes.
Ferguson had five failed fights with Khabib Nurmagomedov.
At UFC 249, Ferguson suffered a one-sided beatdown against Justin Gaethje.
He lost his interim title and any hopes of future title claims.
At 39 years old, retirement might be the best option for Ferguson.