Flora Duffy endured undoubtedly the biggest disappointment of her fledgling career yesterday when she withdrew midway through the Madrid BG World Cup Triathlon, citing fatigue.

The world’s 19th-ranked female triathlete emerged from the 1.2 kilometre swim in the Spanish capital well-positioned among the leading pack and ahead of world number one and eventual winner Vanessa Fernandez of Portugal.

But bizarrely a steep hill right at the start of the bike course appeared to drain the energy out of the 19-year-old’s usually reliable legs, and try as she might she just couldn’t find the power or the rhythm that she’s demonstrated repeatedly at previous World Cup events.

To her credit, despite feeling well below her best she persevered for a time — but as more and more riders sped by, Duffy realised there was something seriously wrong and pulled to the side.

“She was totally and utterly distraught afterwards — probably more upset than I have ever seen her,” said her father Charlie Duffy from Madrid yesterday.

“We’re not really sure what happened or why she fell away on the bike. She came out of the water in around seventh or eighth, which was not bad at all really — about normal for Flora.

“But as soon as she got on the bike, she said her legs felt really weak and once she got to the top of that steep hill she was basically finished.

“She just didn’t have it on the day, that was the bottom line. Whether it’s over-training or her age or whatever, we don’t know, but what we’re hoping is is that it’s a one-off — just a freakish bad day that she’ll learn from and move on.

“The races come thick and fast after this. There’s another World Cup race in Des Moines (Iowa) in two weeks’ time and then she goes to the Pan-Am Games in Brazil.

“So we’re hoping that this is just a one-off and she’ll be back to her old self for the next race — though I guess we won’t really know for certain until she’s raced again and performed to the high standards that we know she’s capable of.”

Nobody can dispute that Duffy’s rise from a talented youngster with enormous potential to a world-class triathlete has been meteoric.

Only 15 months ago, practically nobody in professional triathlon had heard of the blonde-haired girl from the tiny island of Bermuda.

Now though, along with her teenaged rival Kirsten Sweetland of Canada, the eyes of the triathlon community are trained on virtually their every move during major international races and the pressure, expectation and media attention have increased ten-fold.

And after almost a year and a half of constant success stories — which culminated last month in a career-best sixth place at the Lisbon World Cup — her father conceded yesterday that she was almost destined to come crashing back down to earth at some stage.

“The success she’s enjoyed since she started competing in World Cup races has been pretty phenomenal, so there was always likely to be a bad day around the corner,” he said.

“It’s just unfortunate that her performance here was so phenomenally bad. But in a way this might be good for her. We asked her afterwards whether she would come back to Madrid to race and she immediately said yes, she would be back here next year even more determined to do well.

“So that’s a good sign, as is the way in which she has reacted to this.

“It’s hit her very hard, but once she’s had a chance to rest and reflect on what went wrong and have a chat with her coach in the UK, hopefully she’ll be able to turn it around.”

Yesterday’s women’s race in front of thousands of spectators in Madrid was again won by the seemingly unbeatable Portuguese Fernandez in a time of two hours, seven minutes and 33 seconds — almost a minute ahead of her nearest rivals.