England and South Africa will hope lady luck does not desert them when they clash in the Champions Trophy semi-final at the Oval in London on Wednesday. Both sides, aiming to end a frustrating wait for a major one-day title, are fortunate to make the last four in the eight-nation tournament, saved either by the weather or their rivals' bad luck.

South Africa sneaked a tie -- and gain a valuable point -- at Cardiff last week when rain forced the game to end with the West Indies on the exact Duckworth-Lewis par score of 190-6 in 26.1 overs. If Keiron Pollard had not been dismissed off what turned out to be the last ball of the match, the West Indies would have won the game and qualified for the semi-finals after being ahead of the D/L target at that stage.

England were lucky the weather favoured them in Cardiff on Sunday as the hosts squeezed out a 10-run win over New Zealand in a game reduced to 24-overs-a-side due to rain. A washed-out match or a defeat would almost certainly have knocked England out of the race and lifted the Black Caps into the semi-finals along with either Sri Lanka or Australia.

Eventually, England topped group A by virtue of a superior net run-rate over Sri Lanka, who drew level on four points following a 20-run win over defending champions Australia at the Oval on Monday. Last year, England and South Africa drew a one-day series 2-2 after the Proteas came back from a 2-1 deficit to win the final game at Nottingham by seven wickets.

South African captain AB de Villiers said he expected another close contest between two "world-class" sides. "England will be the favourites because they are playing at home and know the conditions well," de Villers said on Tuesday. "But I think it is pretty much 50-50. It's up to the team which rocks up with the right attitude that can take that momentum early on and run with it. We'll be looking to do exactly that and adapt to conditions as quickly as possible. England are a world class team and so are we. It's going to be a great game."

The South African captain said the only way his team can get rid of the label of 'chokers' was to win the tournament. "I believe all teams choke in certain situations," he said. "It's just that somehow we managed to get that tag behind our names. Unless we win this tournament, people will continue to say we are chokers. But it is not something that bothers us." De Villers said premier fast bowler Dale Steyn, who missed two of the three games due to a side strain, was "close to 100 percent" fit, but insisted his team can win even without him.

England skipper Alastair Cook said his team was excited about playing in a major semi-final. "It's such an exciting place for a player to be," he said. "We have come here to try and win the tournament. We have got an amazing opportunity to try and do that and both sides will be excited about that. "It's another day tomorrow. It's another game. What's gone on in the past has no relevance." Group B winners India and Sri Lanka meet in the second semi-final in Cardiff on Thursday in a repeat of the 2011 World Cup final in Mumbai which the Indians won.