The Cork middleweight takes on former champion David Lemieux in one of the chief support bouts of the highly-anticipated Gennady Golovkin v Canelo Alvarez WBA-WBC title rematch.
A WBA world title final eliminator, the winner of the fight at the T-Mobile Arena will be next in line for the winner of the main event.
O’Sullivan and Lemieux are expected in the ring tonight at 2:00am (Irish time), with coverage beginning at 11:30pm and the main event taking place at about 4:00am.
The biggest boxing event of the year, the Golden Boy card is being shown in 160 countries around the world.
Viewers in Ireland are some of the lucky few that will be able to view the card without shelling out a pay-per-view fee.
The card will be shown live on eir Sport 1.
Sky TV customers who have eir Broadband are entitled to eir Sport for free on their box. The channels can be unlocked by clicking HERE.
eir Mobile customers have access to eir Sport via the eir Sport app which can be found in the App Store and on Google Play.
Alternatively for those with Sky TV but without eir Broadband or eir Mobile, the fight can be viewed by subscribing to eir Sport which costs around €30 a month. This can be done here https://subscribe.eirsport.ie/
The feed will be that of BT Sport, meaning Paul Dempsey hosting in studio alongside panellists Steve Bunce, Richie Woodhall, and David Haye, and with Barry Jones and John Rawling on the mic in Vegas.
Viewers in Northern Ireland and Britain will have to pay for the fight via BT Sport Box Office at a cost of £16.95.
Depending on you TV package there are a number of ways to book the fight
– BT TV customers and BT Sport subscribers pay using their remote control
– Sky customers (without a BT Sport subscription) can register and pay online at www.bt.com/sportboxoffice.
– Virgin TV TiVo and V6 customers can use their remote (Home -> On Demand -> Live Events) to purchase the card.
For those that will be unable to watch the fight, Irish-Boxing.com will be posting a full fight reports within minutes of the closing bell.