England made a promising start in their quest to retain the No.1 Test ranking and square the Investec Series, reducing South Africa to 262-7 by the end of day one of the third and final Test at Lord's.
Steven Finn justified the selectors' decision to retain him on his home ground as his momentum-shifting three-wicket burst before lunch gave England an early stranglehold in a Test they must win to stay at the summit.
The Middlesex paceman removed Alviro Petersen, Hashim Amla and Jacques Kallis in the space of seven balls to leave South Africa reeling on 54-4 in the morning session, and James Anderson continued his love affair with Lord's with three wickets himself, moving within one of 50 Test scalps at HQ.
JP Duminy led a South Africa fightback, though, sharing half-century partnerships with Jacques Rudolph (42) and Vernon Philander (46no) to post 61 - his highest score of the series - although his dismissal shortly before stumps ensured England ended the day the happier of the sides.
After losing the toss and being asked to bowl first, England exploited seam-friendly conditions superbly to make Graeme Smith's decision to bat look a curious one.
Smith, setting a new world record as captain for the 94th time in a Test match, was the first wicket to fall, but only after an eagle-eyed review from England.
Attempting to drive a full and wide Anderson delivery well away from his body, the South Africa skipper hit the ground and then the ball, giving Matt Prior a catch behind the stumps to set England on their way.
Petersen survived a close lbw referral when on 12, but the batsman's luck was to run out in the 19th over as Finn suddenly hit a hot streak on home soil.
With the ball angling into leg stump, Petersen was hurried for pace and could only glove a leg-side catch to Prior, who athletically dived to his left to claim the catch. Replays showed that Peterson's bottom hand had left the bat before impact with the ball, however his request for a review had come after replays had already been displayed on the big screen.
There was no doubt whatsoever about Finn's next wicket three deliveries later, though. Amla, who became South Africa's first triple centurion on his last trip to London, had no answer to a delivery which nipped back up the slope and crashed into off stump.
With the wind in his sails Finn soon had a third wicket to his name and it was the prized scalp of Kallis - albeit in controversial circumstances.
The South Africa stalwart became the second batsman to go caught-behind down the leg side but only after England had yet again reviewed umpire Kumar Dharmasena's initial not-out verdict.
Despite a lengthy delay, third umpire Rod Tucker deemed that Kallis' hand was on the bat when he gloved through to Prior, although replays suggested otherwise. The verdict left South Africa in deep trouble.
After a delayed start to the afternoon session, because of a lunchtime shower, England were on the other end of the next DRS ruling when Hawkeye could not overturn an lbw reprieve for AB de Villiers off Anderson.
It cost England their remaining review, but no runs - Anderson concluding a sequence of 13 dot balls to De Villiers with his wicket, well caught by Alastair Cook away to his left at third slip, to end a stand of 51 with Rudolph.
Another half-century partnership frustrated England further as left-handed duo Rudolph and Duminy cashed in as batting conditions improved.
Rudolph looked primed for back-to-back Test 50's before inexplicably playing Swann on to his stumps to hand the England off-spinner his maiden Test wicket of the series and first in 88.3 overs.
Philander flexed his muscles the moment he arrived at the crease and took South Africa past 200 with a streaky edge over gully off Stuart Broad, who struggled to find his rhythm all day.
The runs flowed without alarm but the arrival of the second new ball immediately brought England their seventh success of the day and Anderson's third.
Duminy, who had complied a chanceless 61, perished just three balls into the 81st over when a loose waft well outside off stump was snapped up by Prior.
Bad light brought the players off 14 deliveries earlier than scheduled and South Africa will be hoping Philander and Dale Steyn (21no) can take the tourists past 300 on day two.