Conor McGregor’s defeat to Nate Diaz at UFC 196 was a devastating loss for the poster boy of MMA.

Not a career ending one, though. Far from it.

Saturday’s rematch should surpass the 1.5m pay-per-view purchases the first fight attracted and could even break the record set at UFC 100 in 2009.

McGregor’s aura as an unstoppable fighting force may be damaged after his 15-bout win streak was ended, but his status as the sport’s main attraction remains.

The same can be said of Ronda Rousey, whose next fight will undoubtedly gain a huge audience even after her brutal knockout defeat to Holly Holm in November.

The UFC’s biggest stars are stable – their appeal cannot be derailed by a single defeat.

That is because they are built on a foundation not merely of unbeaten records and title belts, but also a sense that they are always willing to fight anyone.

UFC President Dana White has created a gladiatorial mystique around his fighters by picking the match-ups, pitting the best in the company against each other.

White turned McGregor and Rousey into global icons. And it is their stardom that has helped MMA gain huge popularity in recent years.

Boxing, however, is struggling after years of its top names ducking dangerous opponents and racking up easy victories.

They seem to live in fear that their next defeat could spell the end of their time at the pinnacle of the sport. It wasn’t always this way.

Floyd Mayweather and Manny Pacquiao were stars on the same level as McGregor and Rousey.

A meeting in their prime would have attracted more fans than any fight since Lennox Lewis fought Mike Tyson in 2002.

Instead, they avoided each other and padded their records against inferior fighters.

When the two finally fought last year - six years after they first opened negotiations - both were past their best. It was a missed opportunity.

And while Mayweather retired with an unblemished 49-0 record, few fans will forget that he ducked Pacquiao at his peak.

In the absence of Mayweather and Pacquiao, boxing is missing a recognisable figurehead that transcends the sport in the way that the UFC’s big draws have.

Canelo Alvarez, often tipped as the new face of boxing, is still yet to record a defining victory in his 48 bouts as a professional.

A super fight with pound-for-pound champion Gennady Golovkin would be the most high-profile match-up the sport can currently offer.

Alvarez, though, has been unwilling to risk a second defeat of his career after losing to Mayweather in 2013.

With 32 knockouts in his 35 wins to date, Golovkin should, on merit, be the star that the sport needs.

His own ability has cost him, though, as modern-era fighters are reluctant to enter the ring with him and risk a crushing defeat that could limit their future big-fight opportunities.

Boxing remains more popular than MMA - for now at least.

Mayweather’s fight with Pacquiao attracted 4.4m pay-per-view buys – almost three times as many as McGregor’s last bout.

But the two sports are clearly on opposite trajectories, and boxing must learn from the UFC.

Great fighters are defined by what they do in the ring, not their records, so boxers must erase the fear of failure that is holding the sport back.

McGregor isn’t afraid to lose, and they shouldn’t be either.