AKIPRESS.COM - Holly Holm has caused a sensational upset in UFC 193, knocking out the superstar of the sport, Ronda Rousey, in the second round.

The underdog dominated the fight before knocking Rousey to the canvas with a crunching left-foot kick 59 seconds into round two, reports ABC.

Holm made a blistering start to the bantamweight title fight in from of 56,000 fans at Docklands Stadium in Melbourne, becoming the first fighter to win a round against the former judo champion.

Rousey's past three fights had lasted 64 seconds in total but Holm proved a far more serious challenger.

The former boxing champion stung Rousey with a series powerful jabs in the opening round, but more importantly managed to keep the ex judo champion at a distance.

Some crushing overhand lefts from the southpaw landed right on the button and left Rousey's face bloody, with the underdog clearly taking the points in round one. 

Rousey finally managed to get closer to her opponent in the second round, but that only allowed Holm to dish out more punishment.

Holm had Rousey staggering with some brutal left hooks, before finishing her off with a perfectly executed left-foot kick which landed flush under the champ's jaw.