Graham Thorpe has set England's sights on batting past lunchtime on Monday against South Africa to try and force a draw in the fifth Test.
"We've got to hang in there again," said Thorpe, who was unbeaten on 32 overnight after a stand of 85 with Andrew Strauss on day three.
"We've got to bat out the first session into the afternoon and we'll go a long way to making the game safe.
"It was a shame to lose Straussy - that was the one downside to the day."
Strauss was caught behind for 44 just before a second storm struck Centurion Park, providing a first wicket for the impressive Andre Nel.
"I tried to hang in there with Straussy and got a bit of a partnership together," Thorpe added.
"That dampened their spirits a bit but they've come hard at us today.
"It's hard to keep making starts when you come back in for rain and go back out again.