Hauss raced superbly in his fifth try at the Mooloolaba race to beat Birtwhistle by less than 20 seconds, with Spain's Vicentre Hernandez in third place.
It was Hauss's fourth trip to the podium at Mooloolaba but his first to the top step.
"I never win here until now," Hauss said.
"My last effort was a fifth so I am really enjoying this victory and I knew I had to win this race one day.
"I kept pushing and I made the gap and held on and got the victory.
"I took the lead after the first lap into the run and the pace wasn't fast and I felt okay to go faster.
"I believed in myself and managed to get the win, which I am very happy about.
"I am getting back in the rankings and it is good for confidence and is very good for the preparation, but my main goal is qualification for Rio."
Hauss hit the lead during the run and managed to maintain a gap to the fast-finishing Birtwhistle, who showed he was more than capable of mixing it with the some of the best in the business.
Birtwhistle has put his hat in the ring for Olympic selection in his first year racing against the elite men. He won the OTU Sprint Triathlon at Wollongong last weekend after taking out the Oceania championships in Devonport in February.
The 20-year-old, based in Wollongong, said he was ecstatic to claim runner-up honours in his first attempt at the Mooloolaba event.
"It was amazing out there to hear your name all round the course and to see so many familiar faces and the not so familiar - it was great to have that support and the recognition," he said.
"IT'S pretty exciting moving ahead.
"The start played a pretty big role, the long beach run into the water. I was probably in the top 10 going around the first buoy, which is a great result for me.
"I was able to work pretty hard on the first lap of the bike and join the front group as it stood at the time, and eventually to be caught by the chase group."
Birtwhistle claimed 11 national medium-distance running titles as a junior and said his noted track prowess proved to be a big help yesterday.
"I'm pretty confident with my kick, coming from my track background, and I knew I would have that extra gear no matter how tired I was," he said.
"Hauss is a very experienced guy and an athlete I admire quite a lot and to finish within just a few seconds of him on the finish line is a great result.
"Second is a great result. Obviously I would have liked to get the win today, but in the grand scheme of things I'm pretty happy with today."
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