Rated as an $8 underdog, Moloney put in a brave performance in Las Vegas against one of the world's best pound-for-pound fighters.

But Inoue, who is known as the Monster, had too much speed and power for Moloney and ended the fight at the end of the seventh round with a brutal head shot.

The Melbourne product was taken to hospital following the scheduled 12-round fight as a precaution.

Despite not setting foot in the ring for a year due to injuries and the COVID-19 pandemic, Inoue was locked on from the start and extended his perfect record to 20-0.

Aged just 27, Inoue was compared to legendary Filipino boxer Manny Pacquiao by commentators for the way he completely controlled the fight.

Moloney took serious early punishment, but the 29-year-old survived far longer in the ring than many others have against the indomitable Inoue.

The winner landed 107 punches to Moloney's 62 as he powered to his 17th victory by knockout, many of those coming within the first three rounds.

Moloney was taking a second shot at the WBA and IBF world titles after losing by a controversial split decision to Puerto Rico's Emmanuel Rodriguez in 2018, his only previous career defeat.

Inoue said he was satisfied with how he delivered the final punch to finish off the Australian.

"Moloney has a great defence and it was very difficult to get through," the champion said.

"As you go through fights, you learn things from previous fights and I think I'm getting wiser and better."

Australian Associated Press