The Australian, riding her 11-year-old mare California, earned a standing ovation at the 02 Arena as she defeated a field crammed with the world’s best showjumpers.

Competing over obstacles of 1.60 metres, the highest level of difficulty, Tops-Alexander - who followed a clear round with a second round in which she incurred only four faults – was followed home by Germany’s Ludger Beerbaum and Frank Schuttert of The Netherlands.

By the time Tops-Alexander arrived in the Arena as the last rider to complete the second round, she had to displace Beerbaum, who, after incurring four faults in his first round, had taken the lead on Casello with a clear round on his second circuit in a time of 61.56sec.

A mistake halfway through registered four penalty points, but the Australian rider then showed her nerve and competitive nature as she accelerated through the rest of the course without further penalty to clock a winning time of 61.08.

Schuttert, riding Chianti’s Champion, also finished on four penalty points, with a time of 64.91.

Daniel Deusser of Germany, on Tobago Z, was fourth with a best time of 59.20 but with eight penalty points.

One place behind was this year’s Tour winner, Ben Maher of Britain, who had a best of 59.40 but also registered eight penalty points.

"I planned to finish flawlessly, but it didn’t work," said Tops-Alexander.

"I had seen the results in advance, but not the rides.

"According to time differences, I knew Ludger had to go quickly, but I did not know where he was going.

"I was not sure until the last jump whether it would be enough to win.

"This event has been truly unique, a milestone in our sport."

Tomorrow is due to see the conclusion of the Global Champions League Super Cup, which will be contested by six teams, of whom Madrid in Motion were the top qualifiers.