Norsgaard rode off the wheel of Lorena Wiebes (Team DSM) in the finale, too quick to the line for second placed Marianne Vos (Jumbo-Visma) and third placed Coryn Rivera (Team DSM) in what was a fast-paced course around Lake Como.
Movistar were able to put together a stellar team performance to set up Norsgaard in the sprint, which the 21-year-old credited as the main reason for her win.
“This is amazing, it could not have gone any better," Norsgaard said.
"I am so proud of my team and myself, they always do a fantastic job, and this is the result of really good teamwork.
“I am really enjoying it here and love doing the Giro. The goals for the next days are maybe another win or another podium. And we have (Katrine) Aalerud who is a really good climber, I hope for her on stage 9."
Anna van der Breggen (Team SD Worx) again remained in the maglia rosa but lost her lead in the points classification to Vos as a result of the latter's third place finish.
Amanda Spratt (Team BikeExchange) is the highest placed Australian on GC in 12th position overall, 7 minutes and 56 seconds off van der Breggen.
The longest stage of the race at 157 kilometres, distance didn't discourage the riders from setting a scorching pace as solid breakaways failed to form through the first 43 kilometres from the start in Colico.
The first attack of the course by Lauren Stephens (TIBCO-Silicon Valley Bank) stretched out a brief 15-second gap to the peloton, but it was quickly reeled in before Elisa Longo Borghini (Trek-Segafredo) and Ashleigh Moolman-Pasio (SD Worx) opened the race up with 60 kilometres to go.
The two riders widened the gap to as much as 2 minutes and 25 seconds before they were eventually chased down with 13 kilometres to go as Team DSM and Jumbo-Visma led the pursuit at the front of the peloton.
Australian Sarah Roy (Team BikeExchange) tried an attack on the short ascent to the finish in Colico with 4 kilometres to go followed by Tiffany Cromwell (Canyon-SRAM) but it was again a short-lived break as the two were reeled in inside the two kilometre mark.
A tight battle for the finish began to form as DSM, Ceratizit-WNT, Canyon-SRAM and Trek-Segafredo all positioned their sprinters for their respective lead-outs as Norsgaard floated in the group trying to find the best wheel.
As the riders hit the straight, Stage 5 winner Wiebes executed her lead-out for Rivera to go through, but Norsgaard latched on and had the faster legs to hold off the American and Vos at the line.
Watch the highlights from the Giro d'Italia Donne on SBS from 3:30pm weekends or 4pm weekdays (July 3-12) or available earlier via SBS On Demand and the Cycling Central website.