England ended day two of their second Test meeting with South Africa all out for 205 runs in their first innings, leaving them on the brink of defeat.
The hosts lost their final seven wickets for just 62 runs, meaning that Joe Root's 78 at Trent Bridge will likely count for little in the grand scheme of things.
Root's departure to Vernon Philander, ending a solid stand of 83 with Gary Ballance (27), saw England collapse from 143-4 to 205-10 come the end of play in Nottingham.
Chris Morris and Keshav Maharaj took three wickets apiece, while Philander ended on 2-48.
South Africa, who trail the four-match series 1-0, closed on 75-1 when brought in for their second innings, giving them an overnight lead of 205 - Dean Elgar (38) and Hashim Amla (23) adding 57 after Heino Kuhn was caught for eight runs.
Daniel Lewis
