Mayer, whose defence of his world title in Doha last year ended in tears when he was unable to complete a pole vault because of injury, finished as a clear winner at his training base in Montpellier with a score of 71 in an event that involved three athletes competing separately and connected through a live video feed.

Behind him was Niklaus Kaul, the German athlete who won the world title in his absence – becoming the youngest to do at the age of 21.

Based in Mainz, he totalled 63 after a late surge in the final discipline, where he put up the best performance.

Third place on 61 points went to the US-based Estonian Maicel Uibo – operating in 28C and high humidity in Clermont, Florida - who took silver behind Kaul in Doha.

According to event commentator Rob Walker, Uibo's wife Shaunae Miller-Uibo - the Olympic 400m champion who was beaten to world 400m gold last year by Bahrain's now provisionally suspended Salwa Eid Naser - was looking on in Florida while observing social distancing rules. 

Uibo said before the event that he would not be answering questions on that topic.

"The shuttle run was not as tough as a 1500 metres," Mayer said as he recovered from his exertions.

Asked by insidethegames when he would expect to compete in his next decathlon, he responded: "I would hope that will happen in December because I want to organise something really great for Olympic qualification then, and you two guys are of course very welcome. 

"So I think in December you will see a decathlon."

The competition began with the pole vault where the athletes attempted to make as many clearances of 4.00 metres as possible during a 10-minute period.

They then moved on to the shot put where the challenge was to send the 7.26kg iron ball beyond a 12-metre line as often as possible, fetching it back for themselves, again during a 10-minute period.

The triathlon concluded with a shuttle run competition in which two cones were placed 20 metres apart, with the athletes collecting points for each completed back-and-forth shuttle over the course of five minutes.

The points scored in each event were tallied to determine the winner of an overall event that took an hour and got underway at 5pm CEST.

Britain’s former world record holder Daley Thompson had cast his eye over the prospects ahead of competition and forecast that the trio would be able to manage between 10 and 12 efforts over 12m in the shot – given that all three have managed more than 15m, and Mayer has a best of 17.08.

"They can do it standing – they don’t even have to glide across the circle," he said.

Thompson added: "What is going to sort it out is the shuttle runs at the end. That’s where Kaul is going to come into his own. He’s a brilliant 1500m runner. But he’s going to need to do well there."

Mayer arrived a bit late to the action, discarding a drink and running across to the pole vault runway as his two competitors made their opening clearances.

His request to have those 25 seconds back at the end of the pole vault section was turned down by World Athletics – but as things turned out, with a final successful effort that began just before the clock ticked down to zero, Mayer didn’t need the extra time, winning with 17 clearances from Uibo, who managed 15, and Kaul who went over 14 times.

Mayer extended his lead in the second phase, registering 28 shot put efforts to reach a total of 45, with Kaul scoring 22 for a total of 36, and Uibo managing 20 to reach 35.

Kaul’s status as favourite for the final shuttles derived partly from his performance in sealing victory in Doha last year with a 1500m of 4min 15.70sec, more than two seconds faster than Mayer’s personal best and 10 seconds faster that Uibo’s best.

Kaul completed 1080 metres, with Mayer managing 1040, but the Frenchman’s margin of victory was comfortable.