It was a back-to-back double for the 44-year-old Australian rider

For the second consecutive year she out-paced all her rivals to head the line-up at the Casas Novas Equestrian Centre, where the packed stadium of spectators enjoyed a thrilling 10-horse jump-off.

Last year she came out on top at the same venue with the mare, California, who was just 10 years old at the time.

What made today’s success all the more spectacular was the fact that she was partnering a nine-year-old stallion called Vinchester who was jumping the biggest track of his entire career.

"I never would have believed that this would happen," said Tops-Alexander.

"He only jumped 1.50 metres for the first time earlier this week and today was his first 1.60m!

"If you told me he’d have a few down I wouldn’t have been surprised, so I’m a little bit taken aback."

Runner-up spot went to another nine-year-old, Chalou, ridden by Italy’s 32-year-old Emanuele Gaudiano, while German legend, Ludger Beerbaum, 55,  finished third with his new ride Cool Feeling.

It was Beerbaum’s compatriot Christian Kukuk who set the target over Javier Trenor’s jump-off track, bringing Colestus home in 46.85 seconds when first to go.

Next in, Sweden’s Irma Karlsson looked set to seriously improve on that, but her quick 10-year-old mare Ida van de Bischop misunderstood the instructions on the approach to the remaining two elements of the triple combination and ran past the second element to put paid to their chances.

Faster rounds were then posted by Frenchman Olivier Robert  on Tempo de Paban and by Belgium’s Jos Verlooy  on Igor.

When both Helsinki winner Gudrun Patteet, on Sea Coast Pebbles Z, and The Netherlands’ Leopold van Asten, riding VDL Groep Beauty, left a fence on the floor  it was Verlooy’s 44.24 seconds that Tops-Alexander was chasing.

Despite her horse’s inexperience she took almost a full two seconds off the target time when clearing the line in 42.26sec.

Gaudiano gave it his best shot when breaking the beam in 43.01 with the enigmatic Chalou.

And when Austria’s Max Kuehner and Chardonnay hit the second fence then only Beerbaum could displace Tops-Alexander at the top.

The German has only been riding the 10-year-old gelding Cool Feeling, formerly competed by Canada’s Ben Asselin, since September.

But the man who has taken four gold medals from seven Olympic Games and who has competed in 21 FEI Jumping World Cup Finals is never to be underestimated.

Beerbaum looked well in touch all the way to the final line where a check saw him stop the clock on 43.26  for third place.

Today’s win has boosted Tops-Alexander, who also collected points at the opening leg in Oslo (NOR), to joint-fifth spot in the series rankings.

With 35 points she is within easy reach of a qualifying place for the Longines FEI Jumping World Cup Final in Gothenburg next April.

She is now planning to compete at Olympia, in London in two weeks’ time and then to travel to Basel where the Western European League is set to resume on January 13.