England captain Ben Stokes' bold declaration on the opening day of the first Ashes Test may have come as a shock to cricket traditionalists, but it was "no surprise" to team-mate Jonny Bairstow.

England were 393-8 at Edgbaston, with Joe Root unbeaten on 118 and in superb touch after leading a revival from a mid-innings slump, when Stokes called a halt.

With 20 minutes left in the day, Stokes was prepared to lose the promise of extra runs in the hope of snaring an Australia wicket in the four overs remaining before Friday's close.

There was no breakthrough, however, with Australia 14-0 at stumps after David Warner survived his latest encounter with Stuart Broad, who dismissed the left-hander seven times during the drawn 2019 Ashes series in England.

Stokes has been no stranger to declarations while overseeing a run of 11 wins in 13 Tests since linking up with coach Brendon McCullum last year.

"I'm sure there's many decisions Ben has made that have taken commentators and other people by surprise, but it was no surprise to us," said Bairstow.

- 'Big dance' -
Bairstow played his part in allowing Stokes to make that decision with a run-a-ball 78 in his first Test innings since a freak golf accident in August last year left him with multiple injuries, including three separate fractures in his left leg.

"I'm delighted to be back out there on the big stage, during the big dance. It's something you want to be part of and it didn't disappoint," he said.

Bairstow also helped former England captain Root add 121 for the sixth wicket, with his longtime friend and Yorkshire colleague ending an eight-year wait for an Ashes hundred.

"It was brilliant," said Bairstow. "There are some special traits that he's got and he does special things."

"As someone who has known him for a really long time, been through thick and thin, ups and downs and lots of different things together, it was an absolute pleasure to be out there with him."

Australia paceman Josh Hazlewood, who marked his return to Test cricket with 2-61 in 15 overs, insisted the tourists were not taken aback by Stokes' declaration.

"I think once Joe got his hundred and they were playing a few shots, I sensed it was coming, that's sort of the way they're playing their cricket at the moment," said the 32-year-old seamer.

Hazlewood, back in the side after left-arm quick Mitchell Starc was dropped from the team that beat India in last week's World Test Championship final, was adamant Australia had reason to be pleased with their day's work after losing the toss on a good batting pitch.

"The wicket was –- not a great deal in it, it was very, very slow, not much sideways movement, it wasn't swinging or anything so 390 (for England) and we're 'none-for' so pretty even I would say."