The baby-faced Rabada comes steaming in and there's a solid shout for lbw against Root, hit on the back pad. Worth a review I reckon, but Faf du Plessis decides not to. Good decision.

"Where's the ball, where's the ball?" - an inside edge chopped down onto the crease from Root and he does a pirouette in search of the leather.

Good over from Rabada, England under pressure a little here. Both players yet to score, Root has faced 15 balls.

It was all looking so good for Cook...

Before he drove at Maharaj and ended up edging behind...

Both England batsmen yet to score as Maharaj continues. Malan, forward in defence, sees out the first five deliveries. A charge down the wicket and punch back towards the bowler ends the over. Maiden.

Peter Feet: I suppose it's better than the ubiquitous 49-3!

Malan is in and almost out straight away. Wide from Rabada, Malan down on one knee and drives at air. Lucky not to edge it.

That was such a quality catch from de Kock but must be said it was a decent ball from Rabada, movement off the turf outdone Westley.

England were going along nicely at 92-1. Now it's advantage South Africa, you feel.

Michael Vaughan
Ex-England captain on BBC Test Match Special

That is tremendous from de Kock. The angle could have deceived him and it went sharply. It's not a bad cherry but I think Westley will know he really should have left that delivery. It was a nothing sort of shot.

Maharaj giving it some flight and bowling tightly, a thick edge from Root and the ball trickles over to the leg side. That's the highlight of the over.

The England captain defending well, yet to get off the mark.

Stephan Shemilt
BBC Sport at Old Trafford

When a wicket falls, more happens than just one batsman replacing another. When Cook fell, a security man next to me shouted into his radio. "Charlie four standing, Charlie four standing." C4 is, I think, the stand nearest the England dressing room, so security staff there have to be on their toes when players are leaving and entering the field.

It was a poor shot from Cook, very un-Cook like. He has a hand on his head, leaning against a wall in the dressing room, rolling his eyes and sighing. I don't think he's happy.

That wicket has perked up the South Africa fielders who have a bit of a spring in their step now, lots of clapping and encouragement.

Rabada struggles with his line, but then bangs one in short with Westley bending his knees and ducking well under. Maiden.

Andrew Samson
BBC Test Match Special statistician

Quinton de Kock now has 99 dismissals in Test cricket, in just his 23rd match.

I didn't hear any "Roooooooooot" chants. Maybe they did happen but I have programmed myself to mute them out. Anyway, the England captain walks to the middle and sees off the rest of the over.

Graeme Smith
Ex-South Africa captain on BBC Test Match Special

That's a huge wicket for South Africa. Cook was looking set. It just drifted in the breeze, Cook went for the cover drive, and it's found the outside edge. It was looking flat post-lunch for South Africa, and they needed a lift. Maharaj has given it to them.

Over the rope: Westley's first four partnerships in Test Cricket have all been 50+. Can't complain with that start.

South Africa looking for a breakthrough, Faf turns to Rabada to find it.

Three to Cook who latches onto a wide one and cuts it watchfully past Bavuma at backward point, who considered a dive but wisely opted against it.

Westley on his toes works one off the pads for two more.

I still don't get these fellas on a makeshift bed by the boundary edge. Yes, it's a sponsorship ploy. But just very strange.

Another over of spin races by, Westley happy to play at Maharaj but struggling to get it past the inner circle fielders.

Still some dark clouds over Old Trafford, with the odd ray of sunshine piercing through. We're told the weather should hold up today, but can expect some showers as this match progresses.

Andrew Samson
BBC Test Match Special statistician

The 50 partnership came up from 127 balls. Both times these players have batted together in Test cricket, they've registered a 50 partnership. Taking into account their innings at Essex, they average 57.04 batting together, with six 50 partnerships in 35 innings.