Eoin Morgan's men have the opportunity to vindicate that opinion in game two as they head to Port Elizabeth on the back of their second highest ODI total, a score fuelled by Jos Buttler's magnificent century.
Remarkably, the 73-ball ton was Buttler's slowest ton in England colours, but his promotion to number four mid innings illustrated just how far England have come in the past 12 months.
The rigidity and inflexibility which beset them for years in white ball cricket has been finally been cast aside allowing the likes of Jason Roy, Alex Hales and Buttler to play their natural game and take the attack to the bowlers without fear of retribution.
That was evident in game one where England got off to a flier in the power play and unless South Africa's seamers can find some penetration and discipline it could be more of the same at St George's Park.
The hosts seem likely to call on the talented Kagiso Rabada, rested for the opening rubber, and his inclusion will help bolster a seam attack which looked bereft of confidence or a game plan at the Mangaung Oval. However, the balance of the hosts' side looked out of kilter with the fifth bowling option of part-timers JP Duminy and Farhaan Behardien, milked for 93 runs in just 10 overs as they struggle to match their rivals' talented array of all-rounders.
In fairness to AB de Villiers' side, the toss was pretty crucial, and it could be argued that Quentin de Kock's stunning ton had given South Africa a puncher's chance heading into the final 15 overs of a run-fest.
However, England may not bowl that badly again – Chris Jordan looking particularly ring rusty – and it’s worth remembering that Stuart Broad is waiting in the wings should they wish to make changes.
Having supported England to win the series at 13/8 (now 1/2) it seems a little pointless to back them to win game two, but the 7/2 about Joe Root to top the run-scoring charts still looks attractive.
The Yorkshireman is the glue in the England order and moved serenely to 50 without playing a shot in anger at Bloemfontein before Chris Morris miraculously found some reverse swing to dismiss him.
The offer of 7/2 from Stan James is too enticing to swerve (2/1 Bet365) and the 11/4 generally on offer is still very fair.