Before and during the invasion of the Fire Nation, Poon harassed Iroh because of the latter's military disgrace at Ba Sing Se. He was also confident that Iroh would never escape the prison and was doomed to rot in his cell, never realizing that, the entire time, Iroh had been physically conditioning himself, and faking insanity in the process. During the Day of Black Sun, Iroh, having regained his previous fitness, succeeded in breaking himself out of the prison. Evidently, Poon and Iroh fought each other almost immediately after Iroh busted himself out, as Zuko found Poon lying on the floor, dazed and unable to stand. Poon told Zuko upon arrival that he had "never seen anything like it", and that Iroh had fought like a "one-man army".