Chennai - Shell-shocked England, dismissed as a pub side after their sensational three-wicket humiliation at the hands of Ireland, seek a hangover cure when they tackle South Africa on Sunday. Andrew Strauss's team suffered probably the greatest defeat in Cricket World Cup history when Ireland, inspired by Kevin O'Brien's record-breaking 50-ball century, chased down a 328-run winning target in Bangalore on Wednesday.It was a win which threw the race for quarterfinal places from Group B wide open.England have a win, one defeat, as well as their memorable tie against India, to show from their three matches.South Africa have two wins in two games after comfortable victories over West Indies and the Netherlands. But England off-spinner Graeme Swann has urged England to hold their nerve."If we start panicking and thinking we're the disgrace that half the people on Twitter thought we were on Wednesday night, there's no point in us playing," he said."But to win three-quarters of the game (against Ireland) and throw it away so catastrophically, that's the sort of thing that can ruin momentum."It's in the field where England have problems.They went into the Ireland match keeping faith with senior seamer James Anderson and fit-again Stuart Broad in place of Ajmal Shahzad.They persisted with Anderson despite the fact the swing specialist had conceded 91 runs against India – the most by an England bowler in a World Cup match.It seemed their faith was being rewarded with a tight early spell but, with O'Brien striking the fastest-ever World Cup hundred, Anderson ended up conceding 49 runs in 8.1 overs.Those figures were miserly compared to Broad's none for 73 and with South Africa boasting the world's two leading batsmen in Hashim Amla and AB de Villiers, England face a dilemma over the composition of their attack.Amla and De Villiers both made hundreds Thursday in a crushing 231-run win over the Netherlands, the fourth biggest in World Cup history.For South Africa the momentum could hardly be better as they, like England, seek a first World Cup title.Previous campaigns have often seen the Proteas accused of choking but, with the exception of all-rounder Jacques Kallis, few of the current squad have much in the way of a lengthy World Cup history behind them.Significantly, an attack once over-reliant on fast bowling has been boosted by the inclusion of Pakistan-born leg-spinner Imran Tahir and he could have an important role to play on a Chidambaram pitch set to take turn.And Dale Steyn, arguably the best fast bowler in the world on current form, is quick enough to beat good batsmen through the air."We've got two big games coming our way, England (on Sunday) and then India, so obviously it's good to gain some confidence going into the big games," said South Africa captain Graeme Smith."It's terrific to have guys with pace and a wrist spinner (Tahir) who can polish off the tail. We want to stay one step ahead. We want the guys to be ready."