Only days after the gripping third Test at Lord's, the now-deposed No 1 Test team in the world will fight to retain their No 1 One Day International (ODI) crown against a rampant and ruthless South African outfit, in the first of a five-match series.
The equation is as simple as it was for the final Test that finished with Graeme Smith's men cantering to a 51 run win - lose and you lose top spot. South Africa have the added incentive of absolute world domination; the Proteas were the world's top team in the T20 format going into the series, are now the world's top Test team and could leave Cardiff as the world's top ODI team.
The hosts will be desperate to provide a better account of themselves than they have so far and will call on memories of excellent performances against Pakistan, Australia and the West Indies to regain some measure of form and consistency.
Both teams will welcome new faces to the playing squad, with England likely to make several changes. Alastair Cook will take over as captain from Andrew Strauss for the hosts, with AB de Villiers doing the same for South Africa and relieving Smith of his duties for the ODI side of things.
In addition, South Africa have rested all-rounder Jacques Kallis and called up ODI specialist Faf du Plessis, who many see as Kallis' natural successor. Meanwhile, Wayne Parnell, Justin Ontong and Albie Morkel are all options for the Proteas to consider, should they want to make the game hard to read for their hosts.
The English, meanwhile will look to Steven Finn and James Anderson to provide the incision and wicket-taking ability, in the short version of the game, they sorely lacked over three Tests. Also in the squad are Craig Kieswetter and all-rounder Ravi Bopara; the latter returns after dealing with family problems and is welcomed back by Cook.
England Squad (from): Alastair Cook (captain), Ian Bell, Jonathan Trott, Jonny Bairstow, Eoin Morgan, Samit Patel, Craig Kieswetter (wicketkeeper), Tim Bresnan, Graeme Swann, James Anderson, Steven Finn, Chris Woakes and Jade Dernbach
South Africa Squad (from): Hashim Amla, Graeme Smith, Faf du Plessis, AB de Villiers (captain, wicketkeeper), JP Duminy, Justin Ontong, Albie Morkel, Robin Peterson, Dale Steyn, Morne Morkel, Wayne Parnell, Ryan McLaren, Imran Tahir, Dean Elgar
Where to Watch Live (all times BST):
The match will be telecast live on Sky Sports 1 and Sky Sports 1 HD from 10 am onwards.