Rabada bowls Stokes (58) after promising partnership with Bairstow
Bairstow reprieved on 4 - third umpire controversially rules slip catch didn't carry
Root out lbw for 52 after passing 5,000 Test runs
Skipper survived edge behind on 40 when keeper failed to go for catch
De Kock takes three catches - Cook (46), Westley (29) & Jennings (17)
Cheers, Kal.
Right. That didn't go entirely to plan, did it? You can join Geoffrey in our FaceBoycs live and ask his thoughts on that session. I suspect the word 'rhubarb' will crop up...
So, as the players take a tea break, I'll do the same and hand you over to Amy Lofthouse.
Root 34, Stokes 1
Ben Stokes coming in earlier than he, or England, would have expected.
Maharaj tossing them up, Stokes gets off the mark with an edge well wide of slip.
Three from the over and that's the end of the session. South Africa's session.
Phil Tufnell
Ex-England spinner on BBC Test Match Special
What were we saying five minutes ago? That was the carrot ball. Morne will always get bounce. Malan's done all the hard work and five minutes before tea, just leave that alone! Instead he's got a nice juicy edge that's carried nicely. He'll be furious with himself.
Image source, Getty Images
Malan c du Plessis b Morkel 18 (Eng 144-4)
Morkel strikes and it's poor from Malan. He had done so well leaving the one before, but this time he has a nibble at a wide one and a thick edge sends the ball to second slip, du Plessis taking a simple catch at waist height. Not what England needed.
Malan again plays with the spin off Maharaj and clips it down to mid-on for a single, bringing up the 50 partnership. These two have done well, they were both on zero as England lost two quick wickets.
The TV cameras pan back to the beds on the boundary edge. They're growing on me.
tms@bbc.co.uk
De Kock's diving catch last Test match (I forget the victim) was only terrific due to his bad feet position - he wrongly straightened behind the stumps and then had to adjust, thus making up for a mistake. That catch however, was perfect!
Alex Spencer
A couple of times in this spell now Morkel has struggled with his line, this time Malan guides the ball fine for four. De Kock was scrambling across behind the stumps, he wanted it. He has already taken a fantastic catch in this session.
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Test cricket at its best. Good batsmen, good bowling. Gladiatorial.
Chris, Dover
A straight one from Maharaj and Root gets forward and manages to connect with the toe of his bat and just about keeps it out. Just a single from the over.
A reminder that we will have FaceBoycs live, external on the TMS Facebook Page at around 15:40 BST. It's your chance to ask questions to the legend that is Geoffrey Boycott.
Phil Tufnell
Ex-England spinner on BBC Test Match Special
Beautiful balance, beautiful weight. That was a stunning shot from Root. What a time for a captain's knock for England. Root will be thinking that if he can hang around today, maybe get another ton, England will be in a good position.
Shot! Root, leaning back in his crease, opens the face of the bat and times the ball behind square for a boundary. A whip off the pads adds a couple more to the England total.
Root has 30 from 53 balls, after taking 15 balls to get off the mark.
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Alastair Cook has never got the credit he deserves as a batman. To average nearly 47 as an opening batsman when playing half his games in England where the ball does more than anywhere else in the world is an unbelievable achievement. His style of play allows lower order batsman to come in and make much easier runs than the ones he has fought so hard for - the 88 in the last game was a perfect example. For me he is one of the greats of the game.
Tom Mounsey, Leeds
There's a bit of sunshine now, it's been coming and going throughout the day.
Maharaj continues to toss them up, Root and Malan not interested in taking any risks as England look to rebuild after those two quick wickets.
One from the over.
It was a slow start for Root, as he waited patiently to get off the mark...
And he survived this rather hopeful review from South Africa a few overs later.
People of Old Trafford, pace yourself - there's still a lot of cricket to go today.
So there is a change in the bowling as Morne Morkel comes in for Rabada.
He strays down leg and Root is happy to flick that off his pads for a single.
In fact it's a single each to the England pair, with Morkel breathing heavily as he walks back to his mark.
Stephan Shemilt
BBC Sport at Old Trafford
Believe it or not, this huge structure is a temporary stand. And it's rowdy. There are bananas, togas and some giant beer snake. I've also seen one chap throw up. Nice.
Image source, Getty ImagesMaharaj doesn't look like a man who is tiring as he continues to hold an end up well for his skipper.
A full delivery is whipped off the legs by Root, there's some shouts of "catch it" aimed towards mid-wicket but there's no danger.
Charles Dagnall
BBC Test Match Special
This has been a fabulous spell from Rabada but you sense it's coming to the end. He's tiring.
Image source, PARoot 22, Malan 9
A wasted review? If it has ended up as clipping the stumps/umpire's review then I guess it was always worth trying your luck.
Three from the over, all of them going to Mr Joseph Edward Root.