The crash on Wards Rd near Darfield was one of at least three crashes caused by black ice last week.
The window cleaner’s employer Andrew Love said his staffer was lucky to escape with only muscle tears.
"The back end stepped out and slid and as it has come off the road it’s dug in ... (rolling) over the top of the fence, over the top of the water race and stopped upside down in the paddock,” Love said.
"I was surprised by how strong the car is, it’s a 2007 Toyota Corolla.
Love arrived about an hour after the 7.30am crash last Tuesday.
He said the ice was "horrendous".
Love said the car had rolled about 40m before stopping.
Darfield fire chief John Chambers said the driver was lucky to walk away.
Love, who lives in Lincoln, avoids Wards Rd because of ice but said the employee was from Christchurch and was just following the GPS, not aware of the risk.
Love said further down Wards Rd there was another car which looked to have spun off the road.
There was another crash on Dunsandel and Brookside Rd which fire brigades from Dunsandel and Leeston attended.
Leeston fire chief Matt Walker said the car had tipped on its side in a ditch with the person requiring extraction
Said Walker: “It’s all about driving to the conditions and being careful of shady patches.”