By Doug Vazquez George Kambosos Jr. is an underdog against Devin Haney for Sunday’s fight that will decide an undisputed lightweight champion for the first time in the four-belt era. George Kambosos Jr. will enter Marvel Stadium in Melbourne in front of what is sure to be an electric crowd squarely in the corner of the native Australian. After his huge upset of Teofimo Lopez in November 2021, Kambosos (+145) will make the ring walk Saturday night (Sunday in Australia) in attempt to pull off another upset over the favored American fighter in Devin Haney (-167). The stakes are extremely high as …