Bell and Bairstow forged 124-run stand as England recovered after being four down for 54.
Jonny Bairstow hit a maiden Test fifty while Ian Bell too added yet another half-century as England recovered from 54 for 4 to end the second day's play of the third and final Test against South Africa at 208 for 5 at Lord's on Friday.
Bairstow scored an unbeaten 72, while Bell made 58 as England were 101 runs behind South Africa's 309 when the stumps were drawn. Matt Prior was accompanying Bairstow with 22.
Bell and Bairstow forged an 124-run stand as England recovered in their first innings.
The hosts were 54 for 4 when James Taylore edged Morne Morkel to Graeme Smith in the first slip. But both Bell and Bairtow played patiently to take England innings forward. Bairstow got to his maiden half-century in Tests in 86 balls. They were 154 for 4 after 54 overs.
England's batsmen struggled on day two, reaching 94 for 4 at tea, with Bell and Bairstow were at the crease on 20 and 19 respectively. England lost three wickets in the second session after resuming on 29 for 1 at lunch.
Earlier in the day, England pacer Steven Finn finished with 4 for 75 as South Africa were bowled out for 309 in their first innings.
Resuming from their overnight score of 262 for 7, the visitors lost Dale Steyn early for 26. Vernon Philander (61) and Morne Morkel (25) added 37 runs for the ninth wicket to take their team past 300. Both departed in the space of five balls.
Philander, more known for his bowling exploits, hit his first fifty in Tests. He was the last wicket to go down.
England, trailing 1-0 in the series, will have to win this match to retain their number one Test rankings.