Bairstow has come to the fore at a crucial time for the hosts, who entered the clash with India on Sunday, June 30 knowing they potentially required back-to-back victories to progress.
The pre-tournament favourites have managed just that largely thanks to their in-form opener, who followed up a superb 111 at Edgbaston by blasting 106 at Riverside Durham as England posted 305/8.
New Zealand couldn’t find similar fluency in response, losing wickets from the start and eventually being dismissed for 186 – although they remain in pole position to join England in the last four with Pakistan needing an unrealistically convincing win over Bangladesh on Friday, July 5 to overhaul them.
For the second game running, England were given a flying start by Jason Roy and Bairstow.
The pair, who boast the highest average of any opening duo in ODI history, added another century stand to their collection by matching one another shot for shot.
Bairstow was particularly harsh on the returning Tim Southee, clipping through midwicket, driving over cover and pulling through the leg side for successive fours to kickstart the innings.
Roy caught the eye with a series of inside-out drives against Mitchell Santner and, such was his fluency, it came as a surprise when he departed, stroking Jimmy Neesham straight to short cover.
It was to set an alarming trend as England’s middle order struggled on an increasingly sluggish surface.
Bairstow belied the conditions to reach three figures, but his teammates were finding life difficult as the innings wore on. Eoin Morgan’s 42 was the next-best score, with Neesham, Trent Bolt and Matt Henry claiming two wickets apiece.
New Zealand lost Henry Nicholls, lbw to Chris Woakes, in the opening over of their chase, before Jofra Archer had Martin Guptill caught behind by Jos Buttler’s superb driving grab down the leg side.
Hope sprung eternal while Kane Williamson and Ross Taylor were batting, but the duo were run-out in successive overs, the former at the non-striker’s end after Wood got his hand to a booming drive and the latter attempting an ill-judged second.
From 69/4, the Black Caps never really had a hope and, despite Tom Latham's 57, managed just 186 as England booked their place in the last four.