England will head to Johannesburg later this week with their 1-0 series lead intact after surviving a scare on the final day in Cape Town.
The middle-order pair dug in for over an hour leading up to tea and when they returned just six more overs were possible when bad light forced the players off with the score 159 for six.
The draw was confirmed by the umpires Bruce Oxenford and Aleem Dar - in his 100th Test - an hour and 15 minutes later although most minds had by then already drifted to the task ahead in the third Test at Johannesburg in eight days’ time.
England can take much confidence heading into that match, most significantly in their series lead, but also after piling up 629 for six in such quick time during the first innings.
Ben Stokes’ destructive double-century – the second-fastest ever in Test cricket – was the obvious highlight while Bairstow’s maiden Test ton was no less significant in his development as they shared a world-record 399-run stand for the sixth wicket.
England’s weary attack will also enjoy more than a week’s break after they shared 211 overs in the field and heat as South Africa confirmed why they are the world’s number-one ranked side.
Hashim Amla’s return to form with his double-century over the course of almost 12 hours plus Temba Bavuma's significant hundred were also reminders that England’s plans to win this series will be fully tested over the remaining two Tests.
The Proteas might yet also welcome back spearhead Dale Steyn and Kyle Abbott at the Wanderers - Vernon Philander has been ruled out of the series - but in their absence England were still made to sweat today.
It was the cloudy conditions that helped to transform the flow of a match that had seen bat completely dominate ball for four days.
The South African attack made full use of it, finding swing and seam movement for the first time in the game, and any suggestion England would enjoy a nerve-free final day were undermined when openers Alastair Cook and Alex Hales fell within the first three overs.
England would lose four wickets on a dramatic morning session and set minds racing.
Root’s reprieve did not last long though as Morris produced an outswinger that beat him in defence and crashed into off stump after a run-a-ball 29.
It was a peach of a delivery and ominous confirmation that the ball was doing more than it had done at any stage during the match.
England’s bad morning was confirmed when Nick Compton chipped a simple catch to Faf du Plessis off Dane Piedt shortly before the lunch break while Rabada shelled a tough chance when James Taylor top-edged a sweep.
If England’s players dined uncomfortably then their appetite was hardly helped when Piedt struck in consecutive overs shortly after lunch.
Stokes was fluent in reaching 26 but his desire to counter-punch proved his downfall when he swept to Morkel on the square-leg rope.
Taylor had confidently crunched Piedt back over his head for a six but as the pressure grew he fell to a bat-pad catch.
That brought Bairstow and Moeen together with more than 50 overs still scheduled to be bowled.
In the end they only needed to survive 22.2 of them as the weather closed in and while Bairstow survived the tightest of stumping appeals – which took third umpire Rod Tucker five minutes to muse over – they were largely untroubled in confirming the draw.