Devin Haney became the undisputed lightweight champion Sunday afternoon at Marvel Stadium in Melbourne, Australia, with a unanimous-decision victory over George Kambosos.

Haney (28-0, 15 KOs) used his excellent jab to dictate the pace en route to the win via scores of 116-112, 118-110 and 116-112.

Now, the 23-year-old from Las Vegas owns all four 135-pound titles after the dominant performance against ESPN's No. 1 lightweight.

Kambosos, a 28-year-old from Sydney, Australia, can choose to exercise his contractual right to an immediate rematch with Haney later this year in Australia.

Round 12: Close round as Kambosos makes one final push, but it's a formality. Haney too sharp, too good. He wins the final round and the fight. Now we see if the judges agree. 10-9, Haney. 118-110, Haney.

Round 11: Haney uses the jab to contend with the hard-charging Kambosos, who lands a few solid shots, but Haney makes him pay this time when he misses. 10-9, Haney. 108-101, Haney.

Round 10: George Kambosos continues to press forward in an attempt to land one big shot. He's doing his best work of the fight in the late stages. 10-9, Kambosos. 98-92, Haney.

Round 9: Kambosos finally wins a round on this card. He's pressing harder and breaks through with a few effective shots. Haney's right eye now swollen. Haney faded in wins over Linares and Diaz. Can Kambosos rally? 10-9, Kambosos. 89-82, Haney.