Only about 25 riders were able to steer clear of the chaos that unfurled around a left-hand turn about 24km from the finish in the women's World Tour season-opener at Geelong.

Lippert (Sunweb) then attacked from a small lead group in the closing kilometres and finished clear of her rivals.

Defending champion Arlenis Sierra (Astana) was second, with Australian champion Amanda Spratt (Mitchelton-Scott) third.

"Most of my team crashed, some of them held it up, but from that point on it was a bit surreal," Spratt said on Saturday.

"The team had positioned me really well right at the front so I even heard the crash.

"We just came around the corner and went up the next climb and I looked around and there were only 25 riders left and daylight behind.

"It was so fast. There was no avoiding it if it happened in front of you."

Lippert's win continued a strong run of form for the 22-year-old after she finished second overall in last month's Tour Down Under.

It was her maiden victory on the World Tour and the first time the elite series had started in Australia.

"I was really confident going into this race and my whole team had a lot of trust in me," Lippert said.

"I did a risky attack because it's so long, especially when you're alone, but I felt really strong and I kept on going and I made it.

"It's amazing. I still can't believe that I won my first World Tour race."

Riders weren't the only ones affected by the wet conditions: host broadcaster the Seven Network's helicopters were grounded, limiting the range of pictures available for viewers.

Australian cycling great Robbie McEwen, who was part of the broadcast team, sent through live pictures via Skype for a long period from the back of a motorbike near the lead group.

Better conditions are expected for Sunday's men's race, with a maximum temperature of 23C forecast.

Australian Associated Press