“It takes quite a bit to get me off the park. Yes, it was sore but the circumstances of the game, it was one of those where it was a decision I made to stay out there,” he said. “The medics can give you advice but you’re playing in an Ashes Test match, New Year’s Day Pink Test match at Sydney in front of a big crowd, it’s going to take a lot to get you away from that.”

Speaking after play had finished, Bairstow said he was “extremely proud” of his century, which he described as the “hardest one so far” in his career.

“It was tough out there and I’m really, really delighted with it. Obviously they’ve got a very good bowling attack so it was one of those where I’m just delighted to reach three figures for England again.

“I’m very, very proud. It’s been a lot of hard work. You know how much this means to me.

“I’m absolutely over the moon to be really honest. It was the hardest one so far in the circumstances,” Bairstow said.

When asked about how things had been for him over the years, he added: “It’s been tough, you’ve got to dig deep, you really have.

“I’m sure you guys and everyone else will have mentioned the schedule and how much red-ball cricket people are playing leading into a massive series like this, and it’s not just this series, it’s the India series, the India series before that when we were over there.”

The Yorkshireman added he was determined to not to be “too rigid” at the crease as he smashed Australia’s bowlers for 11 boundaries including three sixes.

“You have to delve very deep into things you’ve worked hard on for a number of years. Your technique changes over those years, and you’ve got to pick parts of it and sometimes go back to the bits you looked at a couple of years ago, and that’s exactly what I did this morning with James Foster. We just went to the indoor school and literally had a bit of fun, went back to something from years ago trying not to be too rigid, to be really honest with you,” he said.

Bairstow is a pugnacious irritant – precisely what the tourists have missed this series

by Oliver Brown, Chief Sports Writer, in Sydney

A picture of barrel-chested belligerence, Jonny Bairstow slashed Pat Cummins away for four and ran, arms pumping, almost to the boundary rope to celebrate. He was delirious with happiness, all the frustrations of his five years in and out of this England Test team purged by a century of magnificent, counterpunching defiance. The SCG crowd, give or take a few drunken hoodlums, saluted him as one.

Fans at this glorious ground, its green pavilion roof offset by the now-traditional blaze of day-three pink in the stands, know a statement innings when they see one. By any standard, this was a hundred rich in significance on both a personal level for Bairstow, who had feared on several occasions that his red-ball career was over, and in the context of this moribund Ashes series. It had taken a month, but at last here was an Englishman showing some snarl.

Bairstow was once characterised by Nasser Hussain as a “street-fighting, over-my-dead-body” cricketer. It is these attributes that England have so conspicuously lacked throughout the tour. Too often, the top order has fallen over in pitifully supine fashion, without any hint of aggression in body language or shot-making. It threatened to be a familiar tale when the team spent almost 12 overs marooned on a score of 36 for four. But Bairstow helped wrench them out of their straitjacket. In concert with Ben Stokes, who channelled resilience of his own by scoring 66 with a side strain, he refused to be cowed, absorbing the pressure before gleefully walloping Nathan Lyon over extra cover for six.

The more Bairstow and Stokes warmed to their task, the more it felt like a stirring redheads’ reunion. Memories resurfaced of their Cape Town double act in 2016, when they combined for 399, the second-highest England partnership in Test history. Both naturally prickly, both disdainful of conventional instruction, they can produce a certain renegade magic whenever they are brought together in the middle.

Plainly, both are more than capable of standing up to provocation, too. When a gaggle of sloshed Australian supporters abused them as they trooped off for tea, one yelling at Bairstow to lose some weight, the two simply stared their tormentors down until they retreated. Ashley Giles, the managing director of England men’s cricket, was finding it all very awkward as he tried to play peacemaker, ushering them into the safety of the pavilion.