Expecting between 1500-2000 riders on Saturday, a smaller field turned out to brave the miserable conditions as 30mm of rain fell.
Giddens' hand for changing gears went numb during the ride.
"I was smacking my hand on the handle bar to wake it up."
She stayed with the leading group of elite men's riders until the 65-70km mark, where the race turned off State Highway 5 at Tumunui Rd to head through the Waikite Valley countryside.
"I went with them until the second hill, I got dropped.
"I ran the whole race. It was miserable for everyone."
Giddens crossed the finish line on Fenton St in Rotorua in 2h 43.05m, just 4s ahead of Auckland's Laura Newman-Watt and Taupo's Sam Warriner, the former Olympian and Commonwealth Games silver medallist in triathlon.
Her winning time in the other direction had been 2h 32m, in much better weather conditions. Giddens will return to her professional team in America in three weeks,
Having been based in the north-central area of the United States, racing out of Wisconsin, while also undertaking tours of Central and South America, Giddens is intending to race more in the southern part of the country this year. She has visited 18 states in the union and plans to increase that to 30 in 2015.
Giddens is also studying extramurally through Massey University, so will be sitting her exams in Atlanta, Georgia at the end of the year.
