London: Hashim Amla's unbeaten fifty steadied South Africa as they took a lead of 139 on the third day of the third Test against England at Lord's on Saturday.
At stumps, the Proteas were 145 for three in their second innings -- a lead of 139 - with Amla 57 not out and nightwatchman Dale Steyn nought not out.
South Africa, 1-0 up in the three-match series, only have to avoid defeat to replace England as the world's top-ranked Test side.
Both teams had slumped to 54 for four in their first innings and South Africa were wobbling at 50 for two second time around before Amla, dropped on two, and Jacques Kallis (31) shared a third-wicket partnership of 81.
South Africa lost their first wicket when captain Graeme Smith, who'd made hundreds in his two previous Lord's Tests, missed a sweep against off-spinner Graeme Swann and was lbw for 23.
Amla was fortunate when he glanced Stuart Broad down the legside and diving wicket-keeper Matt Prior just failed to cling on to the left-handed chance.
But two balls later, Broad had opener Alviro Petersen, playing across the line of a full delivery, lbw for 24.
Earlier, England were bowled out for 315 in reply to South Africa's first innings 309, a lead of six runs.
Graeme Swann was 37 not out, sharing a last-wicket stand of 32 with Steven Finn before the fast bowler was last man out for 10.
Jonathan Bairstow fell just short of a maiden Test hundred, bowled for 95.
Morne Morkel, who dismissed Bairstow, led the attack with four wickets for 80 runs in 28.3 overs while fellow fast bowler Dale Steyn took four for 94 in 29.
South Africa lead the three-match series 1-0 and only need to avoid defeat at Lord's to replace England as the world's top-ranked Test side.
Brief scores
South Africa 309 (Philander 61, Duminy 61, Finn 4-75) and 145 for 3 (Amla 57*)
England 315 (Bairstow 95, Bell 58, Morkel 4-80, Steyn 4-94)
Status South Africa lead by 139 runs