The first of these came in the women's BMX final when Colombia's Mariana Pajon, the reigning Olympic champion and outstanding favourite who had looked utterly unbeatable throughout the competition, crashed on the second turn to see her gold medal hopes disappear in the blink of an eye. 

One of her main rivals, Alise Post of the United States also crashed, leaving Post's compatriot Felicia Stancil to cross the line first to take a first American gold of the Games in a time of 41.647 minutes.

“I started well but on the first turn someone fell and I couldn’t escape it,” said a reflective Pajon afterwards.

“These things happen and can only make me stronger.”

Stancil, meanwhile, was utterly delighted to have somehow evaded the crash and got to the finish line unscathed.

While this was a final marred by a sudden moment of explosive action, the women's 10 kilometres open water swimming final was a test of relentless and brutal endurance.

After a grueling two hour-long race, a video was required to split eventual US winner Eva Fabian from Venezuela’s Paola Perez Sierra, after both were awarded the identical time of 2:03:17.0, meaning hundredths of a second were required to separate them.

Ecuador’s Samantha Arevalo Salinas earned bronze a comparatively mammoth one tenth of a second behind. 

After the shock loss which befell Pajon, there were no similar problems for Mexico's Paula Espinosa, as the Olympic silver medal winning diver secure a seventh Pan American Games gold medal with victory in the women's 10m platform for the third Games in succession.

Colombia recovered from the BMX setback with two victories in weightlifting, including for London 2012 Olympic silver medallist Oscar Figueroa in the men's under 62kg event, while Brazil claimed a first gold medal of the Games in the final event of the evening courtesy of under 52kg judoka Erika Miranda.

The US enjoyed more success with a comfortable men's team gymnastics victory, while Dominican Republic in weightlifting, and Ecuador and Cuba in judo were other nations to secure gold medals.

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