JONNY Bairstow hailed day two of England's second Test match against South Africa as "probably the best of my life."

The Bradford-born wicketkeeper-batsman had to play second fiddle to team-mate Ben Stokes for much a remarkable day in Cape Town – a curious position for a man who made 150 in 191 balls to end his hunt for a Test ton.

The pair shared a mammoth 399-run stand – with Stokes eventually out for a record-breaking 258 – allowing England to declare on 629-6 and have the Proteas 141-2 at stumps, for a lead of 488.

Despite the beguiling brutality displayed by Stokes, one of the most memorable moments of the day came when the Yorkshire wicketkeeper reached three figures.

It was a magical moment two generations in the making, with Bairstow's late father David playing four Tests between 1979 and 1981.

''It's probably the best day of my life, I reckon,'' Bairstow said.

''My mum was up there in one of the boxes, my sister as well, it's a special day for all the family – both here and up there.

"Obviously there's my Dad and grandpa, who passed away last year, and family stuff. I'm delighted to get over the line and it was for those guys. I'm absolutely delighted to score it in this new year's Test match at such an iconic venue.''

Stokes made a point of leaving Bairstow alone to soak up the moment – and twice look to the skies – before embracing his partner.

"That was his first Test hundred and you only ever get your first once," he said. "I wanted to let him have that 10-15 seconds to himself to take in the atmosphere, all the crowd on their feet and his team-mates.

"I thought that was the right thing to do."

Stokes admits he may never play another innings as dominant after reeling off the second-fastest double-century in Test history, needing just 163 balls, and finishing with a staggering boundary count of 30 fours and 11 sixes.

"I probably won't play like this ever again in my life whilst playing cricket, but I've done it once so at least I can say that," he said.

"I normally say 'crikey' when I get to 30, to be honest, so I kept on looking at the scoreboard.

"I felt a little bit of pressure coming into the game, having not got many runs under my belt before this, so there was a lot more emotion than I normally show when I got to the hundred but I just tried to keep on going.

"It hasn't quite sunk in yet."

Stokes came out of the traps with remarkable haste yesterday, adding 130 runs in the first session alone, and claimed his success was built around the simplest game plan of all.

"It was 'see ball, hit ball', I guess," he said. "I wasn't thinking of any landmarks as I went along, I was just trying to hit as many boundaries as I could because it was too hot to run."

At one stage captain Alastair Cook sent out a message asking Stokes about the declaration target and Stokes' personal goal of 300. Stokes had a simple response for his skipper.

"I just said it doesn't really matter because I'm trying to hit every ball for six from now on anyway," he said. "Do what you want."