Expectant Pietersen hailed by captain Collingwood

England are determined to repay Kevin Pietersen today by making sure they reach the ICC World Twenty20 semi-finals in his absence.

Paul Collingwood's team will be in the last four as long as they can avoid a wide-margin defeat against New Zealand in St Lucia – unless South Africa first lose to Pakistan at the same venue.

In that event, England will have done enough already by beating first Pakistan and then South Africa on Saturday in the Super Eight stage – each time on the back of Pietersen's half-centuries.

The man himself, meanwhile, has headed back to London to attend the birth of his and his pop star wife's first child – intending to return, as long as there are no complications, for a semi-final on either Thursday or Friday.

Captain Paul Collingwood is in no doubt how much England have owed to their mercurial middle-order batsman during their two wins in Barbados.

"The contributions he's made in the last two games – two man-of-the-matches – have been fantastic," he said.

"His contributions have certainly gone a long way towards getting us into the semi-finals."

The hope is that Pietersen will be back by midweek as a new father, and scenting England's first tournament success in an International Cricket Council event.

"Everything going well, we hope we can get him back as well," added Collingwood. "We're delighted for him. He's about to have his first child. I know what that feels like, so it's great that he can go back and see that."

Pietersen could hardly have left the camp on a happier note after a 39-run trouncing of his native South Africa at Kensington Oval.

"It's just so exciting to win games for England, and be part of a team that everything is going so well for at the moment," he said, having profited from one moment of fortune early in his innings when he edged a ball between wicketkeeper and first slip for four.

"Playing against South Africa – (Mark) Boucher and (Jacques) Kallis missing one through slip – was good fun."

Others played their part for England, notably Craig Kieswetter, with whom Pietersen shared a stand of 94, and spinners Graeme Swann and Michael Yardy, who took five top-order wickets between them.

Collingwood is delighted with the form of his two finger spinners. "They are two completely different types of bowlers," he said.

"Swanny's a normal orthodox flight-and-guile spinner; Yards is a bit quicker but he can still turn the ball and he's dangerous.

"It's a great combination to have, to see the ball going away from the right-hander and the ball coming in. You need that kind of variation in those overs."

Yardy's spin is not necessarily in the classical mould but Collingwood added: "It doesn't always have to be pretty, as long as you do a job. If you stick to your strengths, you can be very effective."

New Zealand, meanwhile, know they could still sneak qualification for the semi-finals after holding their nerve for a one-run win over Pakistan on Saturday morning.