As England left Centurion on Saturday evening they will have taken a glance skywards and seen the mother of all thunderstorms brewing. In the back of their minds is the thought that maybe nature can help them escape the opening Test with a draw, but in these parts the weather is so unpredictable that England can't rely on any favours - and nor should they.

They have been hanging on by their fingertips in this match, but now their grip on any chance of victory has been wrenched free. From the moment Andrew Strauss's decision to bowl first backfired they would probably have settled for a draw. Now they will welcome that result with open arms, by whatever means it comes, and the chance to head to Durban all-square.

However, the captain can have no further influence on the match after he fell to a superb delivery from Morne Morkel in the second over of England's uncomfortable six-over stint. All Strauss can do is sit, watch and ponder. If his team-mates can't bail the side out and save the game, he is going to have some explaining to do. Hindsight is an evil thing, but putting South Africa in has looked a dodgy decision for at least four days.

"Andrew Strauss is a quality player and getting him out early on certainly knocks the team back," Hashim Amla said. "We were hoping for one wicket and fortunately we got Strauss out."

There is a memory, though, that England can cling to during their battle for survival. Five months ago they pulled off a miraculous escape at Cardiff in the opening Ashes Test as the final-wicket pair of Jimmy Anderson and Monty Panesar survived 69 balls. They began the final day in a similar position - 20 for 2 - and looked dead and buried before tea.

"It's going to be a big day for us - very similar to Cardiff in the Ashes," Anderson said. "We pulled through that and we saw what happened after that. That's the sort of momentum we can get to put us in a good position for the rest of the series, if we get through tomorrow, win or draw."

The manner in which South Africa built their lead may have lulled England into a false of security about batting out time to save the game, but the shooter from Anderson that removed Amla will have set alarm bells ringing. The ball doesn't have to roll along the deck all the time; the simple knowledge that it might happen is enough to put doubt in the batsman's mind. Saving the game is going to be a mental battle as well as a technical one for the nine remaining wickets.

"You've got to put the wicket out of your mind, don't think about what could happen with the balls that go underground," Anderson said. "We're going to have to be reasonably positive when we bat and hope we can manage to get through."

Whatever gains England have made during this match they have come when playing catch-up. Graeme Swann's first-innings five wickets were a manful effort, but only served to keep South Africa's total from going out of sight. And while Swann starred again with the bat, shifting the momentum with his thrilling 81-ball 85, South Africa still emerged with a valuable lead.

When the home side slipped to 46 for 4 in the 22nd over, England had their best opportunity to turn the tables but again they couldn't take the final stride into a commanding position. The bowlers tired in the heat and the pitch grew more unresponsive as the ball became older and older.

"We came out reasonably fired-up, and at four-down we thought 'we're in with a sniff here'," Anderson said. "But they really dug in and played well and saw off the seamers' first couple of spells. Then obviously when you come back for the third or fourth spell you don't have the same energy."

Having watched conditions become easier for batting during the day, Anderson knows the opening exchanges in the morning will be crucial. Of equal importance is the fact that South Africa will be able to call on a second new ball with about an hour remaining, should they need it.

"It's going to be a really difficult first hour for us," Anderson said. "That harder ball does do some unusual things, but nothing of the sort happened with the old ball. If we can get through that first hour, we obviously have a good chance of batting the whole day."