Dame Flora Duffy battled her way to a sixth-place finish in the inaugural PTO US Open in Dallas on Saturday.

Among a stellar elite women’s field, Duffy, making her debut in the series, exited the water from the two-kilometre swim in 28min 3sec, clocked 2hr 1min 25sec on the 80km bike course and completed the 18km run in 1:13:40 for a combined time of 3:45:17.

Ashleigh Gentle, who was eighth off the bike and slightly less than seven minutes off the lead, somehow wiped out the deficit, passing Taylor Knibb with just two kilometres remaining to cross the line in a winning time of 3:37:17 and scoop the $100,000 top prize. Her incredible run of 1:04:59 was four minutes faster than any other competitor.

Knibb, who was reduced to a walk over a couple of short sections as the conditions took their toll, held on for second with a 3:38:32 finish with Lucy Charles-Barclay completing the podium in 3:40:31.

Charles-Barclay was soon at the front in the water, with Knibb the only athlete to stick on her feet. The rest of the field were strung out behind them, as the pair came out of the water for the midway exit with a lead of 31 seconds to a group including Holly Lawrence, Gentle, Duffy, Paula Findlay and Lisa Norden.

By the end of the swim, that lead had only increased, with Charles-Barclay and Knibb leaving the water in one minute ahead of the chasers. Charles-Barclay stole a march of around 15 seconds on Knibb through the first transition while the chase pack was led onto the seven-lap bike course by Lawrence, just more than a minute after Knibb.

At around 8km into the 80km course, Knibb surged past Charles-Barclay and began to put distance between herself and everyone else on the course.

During lap two, Charles-Barclay, who had already lost her race nutrition bottle from the rear of her bike, had a brief stop to address an issue with her electronic shifting, which had overheated under the Texan sun.

By halfway through the bike, Knibb’s buffer was 1:51 to Charles-Barclay. In turn, the Brit had a 1:12 gap to the chase group of Lawrence, Findlay, Duffy and Norden, who found themselves just over three minutes adrift of the leader.

By the start of the final lap, Knibb’s lead was up to 3:04, Charles-Barclay holding steady at 2:08 ahead of the chase pack, who by this stage were five minutes behind Knibb.

Meanwhile, Gentle was leading the second chase group, 6:19 from the front and 1:06 from the podium contenders ahead.

Showing no sign of weakness, Knibb pushed on to the second transition and started the 18km, five-lap run with a lead of 3:42 to Lucy Charles-Barclay.

Nearly two and a half minutes later, Findlay, Duffy, Lawrence and Norden began the run shoulder to shoulder. However, it was not long before Duffy upped the pace to take a clear third place on the course.

Gentle, eighth off the bike and 6:52 off the lead, stormed onto the final leg, quickly establishing herself as the fastest runner on the course. Soon, Duffy faltered while the Australian seemed unfazed by the heat overtaking within the first 5km.

From there, Gentle continued to hunt down her rivals ahead, overcoming her deficit to Lucy Charles-Barclay by 10km. Initially, it seemed Gentle would run out of road to catch Knibb, but the American was reduced to a walk over a couple of short sections as the conditions took their toll.

Making the pass just before the 16km mark, Gentle had 2km of running to soak up the fact she would be taking a second consecutive PTO Open victory, having won the opening race in Edmonton.

Knibb held on for second and $70,000 while Charles-Barclay completed the podium to earn $50,000.

Lawrence paced herself perfectly to stay in the hunt for big money, coming fourth in to claim $40,000. Norden’s 3:44:49 finish saw her scoop $35,000, with the Swede pipping Duffy to round out the top five.