Waves gouged out a 2m (6ft) deep hole in the sea wall at Teignmouth in Devon.
The Environment Agency and Teignbridge District Council rebuilt the sea wall despite "challenging" weather conditions.
The agency said the wall breach put Teignmouth homes at risk of flooding, so it was "essential to carry out repairs quickly".
A gaping hole in a seafront promenade smashed by storms three months ago has been repaired.