South Africa's grip on the world No.1 test ranking continues to tighten as England's openers stumbled to 208 for 5 after day two at Lord's.
After bowling the tourists out for 309, with Vernon Philander making 61, England spluttered to 54 for 4 as Dale Steryn (2 for 44) enhanced his reputation as test cricket's No.1 fast bowler with a pair of early wickets.
But Ian Bell (58) and Jonny Bairstow put on 124 runs for the fifth wicket to leave Andrew Strauss' side trailing by 100 runs as their attempts to hold on to their No.1 test rankings remain undermined by their fortunes with the bat.
Resuming day two on 262 for 7, Philander and Steyn (26) kept the hosts at bay until the fourth over of the day, when the latter flayed at a wide delivered from Stuart Broad, and edged to Graeme Swann at second slip.
New man Morne Morkel required little invitation to open his shoulders, smashing four boundaries in a 36 ball cameo of 25 before Finn found his outside edge and Matt Prior took the catch.
And the wicketkeeper took his sixth dismissal of the innings when he stumped Philander as he waltzed down the wicket to Swann.
England began their reply in tentative fashion, and despite using Steyn as first change, captain Graeme Smith was celebrating a breakthrough in the 11th over as Morkel got the ball through Strauss' defences for 20.
Having by now been introduced, it was Steyn's turn to wreak havoc, first as he trapped Jonathan Trott (8) and had Alastair Cook (7) caught by Jacque Kalis as England looked in disarray.
James Taylor (10) then showed hapless defence to edge Morkel to Smith, and at 54 for 4, the home side looked to be relinquishing their No.1 test ranking with a whimper.
The pressure continued to grow, as Bell survived an lbw review, but he and Bairstow, who replaced Kevin Pietersen in the side for the third test accumulated an 124-run partnership to re-build the innings as England clawed their way back into the match.
Bell fell to Philander with an hour of play remaining, as he edged to Petersen for 58, but Matt Prior (22 not out) and Bairstow (72 not out) kept England in contention as they closed at 208 for 5 going into a crucial third day.