England are on course for a place in the ICC World Twenty20 semi-finals after a hugely impressive 39-run victory against South Africa in Barbados on Saturday.
Kevin Pietersen made his second successive half-century as Paul Collingwood's side made 168 for seven at Kensington Oval, with South Africa's batsmen always struggling in their reply.
Spinners Michael Yardy and Graeme Swann took five big wickets for 55 runs between them in a result which leaves England unbeaten in Group E.
They must now simply avoid a heavy defeat against New Zealand on Monday to guarantee progress from the Super Eight stage, regardless of how the Proteas perform against champions Pakistan.
With Collingwood winning the toss, Michael Lumb departed early after a surprise over of new-ball spin from Johan Botha pinned him lbw.
However, Pietersen and Kieswetter responded with all-out attack in a second-wicket stand of 94 in under 12 overs.
Pietersen struck a succession of front-foot fours off the pace of Dale Steyn and Morne Morkel, the former in particular on the receiving end.
Kieswetter, meanwhile, rode his luck and earned two reprieves, the first coming when he was caught at third-man on seven, only for Morkel's delivery to be judged a no-ball.
He was then badly dropped at deep midwicket by JP Duminy having made 29 with his side on 79 for one in the 10th over.
The pair responded in kind to the deliveries sent down on a pacy pitch and Pietersen reached his 50 with his eighth four to go with a six from just 30 balls.
The stand ended when Pietersen (53) swept Botha straight into the hands of short fine-leg - just reward for the off-spinner, who conceded only 15 runs in his four overs.
Collingwood arrived at the crease and soon started lashing out as well, depositing the fourth ball he faced - from Jacques Kallis - into the stand at wide long-on.
Kieswetter (41) struck a similar blow to the opposite corner of the ground from Duminy's first ball of the next over.
However, he then got underneath another big hit to sky a catch to long-on, well held by Steyn.
Collingwood cleared the boundary once again before skying a catch to be caught behind off Morkel, with Luke Wright soon bowled trying to smash a Charl Langeveldt yorker.
The emphasis was therefore on Eoin Morgan to deliver once more and he helped add 43 from the last five overs.
Up against it
At the time, England's total was not as high as they would have wanted and yet it ultimately proved more than enough.
The Proteas were definitely up against it by the eighth over, when the top three had all gone for just 44 runs.
Captain Graeme Smith was third out, chipping a catch to deep midwicket in Swann's first over.
Yardy had already struck by having Herschelle Gibbs sweep his first delivery into the hands of Ryan Sidebottom, who took the catch running and tumbling back from short fine-leg.
Before then, Kallis had mistimed a drive at Stuart Broad straight to mid-off, while Albie Morkel fell to a second-ball duck when he edged on off Yardy.
With South Africa already way off their target, AB de Villiers mistimed a pull at Swann and was caught in the ring.
Duminy and Mark Boucher offered some resistance but by the time they arrived at the crease the work load was simply too high.
As it transpired, they were unable bat out their overs as Sidebottom weighed in with late wickets to finish with the best figures of three for 23.