Direct rail services between north and south Wales are to resume after repair works were completed early.
Floods washed away ballast and track foundations under the line in Herefordshire, Network Rail said.
The first services will run on Saturday, but Transport for Wales warned there may still be delays due to speed restrictions on the line.
It asked passengers to check for updates before they set off.
Network Rail thanked passengers for their patience while the track was repaired.
It was originally thought the route could have been closed until Monday.
Network Rail said the work needed 300 tonnes of foundation and 600 tonnes of ballast.
Chris Howchin, the company's route director, said: "I'm delighted that we've managed to reopen the line ahead of schedule - restoring a vital rail link for Wales and Borders.
"The whole team worked tirelessly in difficult weather conditions and it's a fantastic result for passengers."
The Met Office had issued an amber warning and said more than 4in (100mm) of rain fell in 24 hours in some places.
On Monday, 34 homes were evacuated as the River Wye continued to rise in Monmouth.