Khamzat Chimaev is feeling something few imagined he ever would—the frustration of defeat and the hunger for revenge. The 32-year-old suffered the first loss of his career on Saturday, when he faced Sean Strickland in his first middleweight title defense. Despite entering the fight as the clear favorite, the night unraveled in a way almost nobody expected. In a brutal, back-and-forth war, Strickland’s relentless jab, higher striking volume, and …