Conor McGregor and Floyd Mayweather’s blockbuster boxing bout has not sold-out with tickets still available five hours before the fighters are due to walk to the ring.

Tickets are still available at the T-Mobile Arena in Las Vegas, with prices ranging from $2,500 to as much as $10,000 for ringside seats.

In fact, every section bar one in the upper bowl still has availability, despite thousands flocking to Las Vegas for the biggest fight ever seen financially.

Approaching 04:00 BST [20:00 PT], there were still large areas in the crowd empty, with concerns growing that the main event will play out in front of a small audience.

Both McGregor, the two-time UFC champion, and Mayweather, the unbeaten boxing icon, are expected to earn more than $100m from the bout, yet the failure to sell-out the arena tickets will be seen as a rather embarrassing failure on their part to sell the fight.

Conor McGregor's most memorable quotes Show all 15 1 /15 Conor McGregor's most memorable quotes Conor McGregor's most memorable quotes McGregor on... ... staying humble. Getty Conor McGregor's most memorable quotes McGregor on... ... how he chose to make an honest living. Getty Images Conor McGregor's most memorable quotes McGregor on... ... why he doesn't watch Britain's Got Talent. Getty Images Conor McGregor's most memorable quotes McGregor on... ... bums, and selflessly transforming their respective bum lives. Getty Images Conor McGregor's most memorable quotes McGregor on... ... the exceptionally dangerous solid gold pocket watch industry. RIP to those intrepid horologists. Getty Images Conor McGregor's most memorable quotes McGregor on... ... strangers. Getty Images Conor McGregor's most memorable quotes McGregor on... ... his impressive ability to handle bad news in the wee small hours. Getty Images Conor McGregor's most memorable quotes McGregor on... ... the most lucrative fight in the history of boxing. Getty Images Conor McGregor's most memorable quotes McGregor on... ... the Brazilian people, and how to endear yourself to a foreign culture while traveling. Getty Images Conor McGregor's most memorable quotes McGregor on... ... always staying pragmatic. Getty Images Conor McGregor's most memorable quotes McGregor on... ... Ireland's travelling support. Getty Images Conor McGregor's most memorable quotes McGregor on... ... inventing his own weight-class. Getty Images Conor McGregor's most memorable quotes McGregor on... ... the Deep South. Getty Images Conor McGregor's most memorable quotes McGregor on... ... his recently improved pay packages. Getty Images Conor McGregor's most memorable quotes McGregor on... ... how he took down former featherweight champion Jose Aldo in just 13 seconds. Getty Images

Around 20,000 fans have travelled from the United Kingdom and Ireland in support of McGregor, but many will be watching the fight in bars dotted around Vegas rather than spend the extraordinary fees for tickets to the bout itself.

Despite the sell-out failure, Irish fans have been in good spirits ahead of the main event, with Sin City illuminated in emerald green thanks to McGregor’s loyal fans who have followed him throughout his UFC career an move into boxing.

Super-fight preview: Floyd Mayweather v Conor McGregor

"We've no tickets,” said one young fan in his twenties wearing a green Irish soccer shirt and drinking a beer in the hot sunshine.

"We're going to hit the black jack table and see if we can win enough money to buy some."