One lane of State Highway 6 from Haast to Makarora re-opened on Sunday.
The road closed at midday on Friday after heavy rain began falling in the area, bringing more rock and gravel down on the highway from the Diana Falls slip.
A 25,000 tonne slip had covered the road last weekend, following weeks of closures because of slips.
Pete Connors of the Transport Agency said on Sunday the rain had stopped and contractors had been clearing the road and checking the slip since first light.
He said the agency will continue to close the highway between 6pm and 8am as a safety precaution.