Four years into his 154-year prison sentence, a violent sex fiend — dubbed the “Crackhead Casanova” by Manhattan prosecutors — is asking the same judge who threw the book at him to set him free.

John Hamlett, an unemployed crack-addicted rapist who infamously told his jury, “I had a lot of women, and I spread myself thin,” is seeking to overturn his conviction for two East Village attacks in 2006.

Hamlett claims his former defense lawyer, Seema Iyer, improperly helped prosecutors secure the cooperation of his girlfriend.