Jonny Bairstow hit the highest score of the match to lead an England fightback against South Africa on day two of the third and final Test on Friday, keeping alive their hopes of the win they need to square the series.
England were 208 for five at stumps, trailing the tourists' first innings by 101 runs, after Bairstow's innings of 72 not out in close on four hours at Lord's.
It was his highest Test score in his fourth match.
Matt Prior was unbeaten on 22.
South Africa were earlier dismissed for 309 before lunch, as number eight Vernon Philander made a test best 61, his maiden Test 50, and the same score JP Duminy registered on Thursday.
Steven Finn was England's best bowler with 4-75.
It has so far been a seesaw contest with the game now evenly poised.
Bairstow, who only returned to the team because of Kevin Pietersen's controversial omission, batted with maturity and patience to help rescue England after they had slumped to 54 for four after lunch.
Ian Bell hit a battling 58 and put on 124 with Bairstow for the fifth wicket.
Dale Steyn was South Africa's best bowler with 2-48, while Morne Morkel claimed 2-53.
England must win to draw the series, following their loss by an innings and 12 runs in the first match at The Oval. South Africa will leapfrog them and take over at the top of the world rankings if they avoid a defeat.
Photograph: Jonny Bairstow of England (right) acknowledges the crowd after reaching his half century during day two of the 3rd Investec Test match against South Africa at Lord's Cricket Ground on Friday. (Harry Engels/Getty Images)