England 192 for 4 (Crawley 66, Sibley 44) v South Africa

England's inexperienced openers brought an air of calm after a chaotic start to the fourth and final Test, but a batting collapse after tea ensured the day continued on a dramatic path.

It was an eventful opening day before, during and potentially after play.

As if there wasn't already enough riding on this match, with England closing in on a series triumph and South Africa desperate to salvage something from a tumultuous week that started with an innings defeat at Port Elizabeth, included a confused changing of the guard in the one-day side and ended - if Faf du Plessis had his way - with the captain pleading tunnel vision when it came to answering any more questions about his uncertain Test future.

Rain wiped out the first session and, when word finally came through that a 1.20pm start time was in sight, the players began warming up in the outfield. That's when England's turmoil began.

Jofra Archer, expected to make his return from the elbow injury that ruled him out of the previous two matches after sending down thunderbolts in the nets this week, bowled a few balls and then made a bee-line for the team doctor clutching his arm. He was promptly ruled out of contention, Joe Root claiming upon winning the toss and electing to bat first that the team couldn't be confident their star quick could make it through the match.

Chris Woakes was called into the side and Mark Wood was called upon to play back-to-back Tests for the first time since 2017 as England, understandably, opted for an all-out seam attack at the Wanderers, leaving Dom Bess out despite his five-wicket haul in Port Elizabeth. Horses for courses.

So it was that new opening pair Zak Crawley and Dom Sibley set about compiling England's first century opening stand since December 2016.

Playing just his fourth Test, Crawley continued his steady progress since making his debut in New Zealand in November. After scores of 1, 4, 25 and 44, Crawley - who turns 22 early next month - settled in nicely. A flourish through the covers, a thump through midwicket and a commanding straight drive brought him 12 runs off a poor Dwaine Pretorius over and took him to 45 not out, before he brought up his maiden Test fifty with a thick outside edge through point from the first ball of Pretorius' next over.

His knock wasn't completely smooth, however. Crawley was struck flush on the helmet, right next to the badge, by a ripping 149kph / 93mph delivery from Anrich Nortje not long after bringing up his half-century. He was assessed for concussion and deemed fit to continue as he and Sibley took England to tea on 100 without loss.

Earlier, Sibley had survived being caught sharply by Temba Bavuma at gully for 12 when umpire Joel Wilson correctly called a no-ball on the retiring bowler Vernon Philander, who had overstepped. England were 41 without loss at the time.

South Africa had been lacklustre throughout the extended session to tea but when they returned after the break, they made things happen.

Debutant quick Beuran Hendricks, in the side for Kagiso Rabada who was suspended for an overly robust wicket celebration in Port Elizabeth, made the breakthrough when he had Sibley out, strangled down the leg side for 44.

Crawley followed a short time later when he, like Sibley, offered an non-committal shot and was caught by Rassie van der Dussen at slip, delivering Philander his first wicket of his farewell Test.

That had England at 116 for 2 but their wobble didn't stop there, the tourists ultimately losing 4 for 50 when Joe Denly edged a Dane Paterson outswinger to van der Dussen and Ben Stokes fell in similar fashion, lured into an attempted drive by Nortje and edging to van der Dussen, again at slip.

The theatre continued as Stokes became involved in an angry verbal exchange with a spectator as he walked off and he could yet be called to answer questions from the match referee. After bad light ended play early, Stokes could be seen chatting to members of the crowd and signing autographs on the boundary.

The fact that the day ended with honours pretty much even had appeared so unlikely on the basis of South Africa's performance earlier in the day. That they found some fight was encouraging for their fans after du Plessis suggested this could be his final Test on home soil amid speculation over his playing future.

The intrigue deepended for them when Quinton de Kock was named captain of the ODI side for the upcoming series with England and du Plessis was omitted altogether with uncertainty over whether it was a permanent change. Graeme Smith, South Africa's director of cricket, later confirmed it was the first step in their succession plan and du Plessis would not be reinstated as leader, should he return to the side.

So, with plenty going on off the field - for both sides - the stage is set for more twists and turns on it.