England will prepare for Friday's crunch NatWest Series match against South Africa hoping they have finally found a settled opening partnership to propel their one-day side to success.

Impressive victories at Headingley and Trent Bridge have put England in sight of an unexpected series triumph should they succeed in the third game of the five-match series at The Oval on Friday.

If they complete a hat-trick of victories over a South African side who had won nine successive one-day matches prior to the start of this series, it would be a notable triumph for new captain Kevin Pietersen.

But it would also perhaps mark a significant achievement for opening pair Matt Prior and Ian Bell as they attempt to halt the constant chopping and changing at the top of the order.

"It's obviously a new partnership but we've done well so far," enthused Sussex wicketkeeper-batsman Prior, who hit an unbeaten 45 and claimed a joint England record six catches in Tuesday's emphatic 10-wicket triumph at Trent Bridge.

"A bit like anything, it develops and you get used to running between the wickets and communicating to the point where it will just be a simple nod rather than a call.

"Things like that do happen over time and given the time I think, fingers crossed, it could be a good opening partnership."

If England are to progress and become a one-day side capable of challenging for major tournaments, they need the current partnership to succeed to provide stability if nothing else.

The latest incarnation are the fourth opening partnership tried by England in the 13 one-day internationals played this year and the sixth in 28 games since Peter Moores succeeded Duncan Fletcher as national coach.

They are still suffering teething problems, which was underlined in the opening victory in Leeds when they crawled to a 77-run stand in 20 overs with Bell failing to hit a single boundary in his 35 from 69 balls.

Prior, the naturally more attacking player, appears to have licence to play his shots while Bell is happy keeping the scoreboard ticking over which was demonstrated by the Warwickshire batsman playing a supporting role and contributing only 28 to an unbroken 85-run stand to win the game in Nottingham.

But Prior insisted they do not have preconceived roles, claiming: "I don't think you can have defined roles because there are too many variables.

"We know what we want to do and we know where we want to be at the end of the powerplays and during the powerplays but on different wickets that might adjust slightly against different bowlers.

"There are times when bowlers are allowed to bowl well and they will have good days so there are times you have to sit in.

"There will be days when Ian is absolutely on fire and hitting everything for four and there will be days when I'm clubbing around a little bit and getting ones and twos and vice versa."

He stressed: "I don't think there's a greater emphasis on me taking risks and I personally don't see it that way because I've worked very hard on not risking my wicket.

"As a batter you've got to have pride in the fact you want to bat. You're playing for England, you're representing your country and none of us want to go out there and just throw it away.

"You have that pride and it's something I've worked very hard on to not just give it away, but there are risks you have to take.

"I've had experience of opening the batting for Sussex and if I need a boundary I know what kind of shot I need to play but it's trying to make sure you get the level of risk management right.

"You want a boundary but it's a question of working out which is your best option and to be fair to Ian he stands and plays nice shots and gets boundaries."

The success of the opening pair has matched impressive performances throughout the side during the opening two matches in the series with the return of key all-rounder Andrew Flintoff and Steve Harmison's decision to come out of international retirement.

Stuart Broad's man-of-the-match spell of five for 23, the fifth best figures by an England bowler in a one-day international, set the tone alongside James Anderson with the new ball and ensured Pietersen barely had to use either Flintoff or Harmison as South Africa slumped to 83 all out.

It is an impressive pace battery which may yet become a force in Test cricket and Prior admits he would rather be keeping wicket than taking guard against such a fearsome quartet.

"Stuart Broad and James Anderson have been with England but I've played against Fred and Harmy this summer and for them to be coming on first and second change is fantastic," admitted Prior.

"Jimmy is bowling brilliantly, bowling 90mph, you've got Stuart Broad and then to follow them you have Fred and Harmy and we all know how fantastic they are - it does look really, really exciting."