England captain Jos Buttler rested himself for the decider and would have been happy with what he saw as Bairstow smashed 73 from 41 balls at the top of the order, with six sixes and five fours to his name.
That conjured memories of his match-winning Test century against the same opponents at the same ground last summer, but after he holed out in the 12th over England ran out of steam as they slowed to 175 for eight.
Dawid Malan and Liam Livingstone both made 26 but neither were fully fluent as the Black Caps reasserted control with their spin contingent, who shared six wickets.
Meanwhile Harry Brook, whose hopes of forcing his way into England’s World Cup squad puts both Malan and Livingstone at some risk, could only manage four.
After finishing the England innings with five for 38 in the last five overs, New Zealand came out firing and made a confident pursuit to complete their comeback from 2-0 down with Buttler making an unexpected substitute’s outing behind the stumps after Bairstow reported a niggle.
Tim Seifert (48), Glenn Phillips (42) and Mark Chapman (40no) combined to take down England, who could not keep a check on the boundary count.
The pick of the home side’s bowling attack was 18-year-old Rehan Ahmed, making his debut on home soil after his rapid rise over the winter.
He was sharp and economical with two for 27 in his four-over allocation and also completed a run out, a timely reminder of his promise almost six months since his last England appearance.
The real business is now set to begin, with a ODI series starting in Cardiff on Friday in what represents a final warm-up for next month’s World Cup in India.
But England, whose evening ended with 16 balls unbowled as Luke Wood mis-fielded to gift the winning runs, will need to sharpen up.
Rashid is arguably the greatest white-ball bowler England have ever produced and, even though he has previously intimated he has many more years left, the double World Cup winner turns 36 in February.
He will be back for the T20 series against the Windies this month after being rested for the ODIs, but the hole left by the Yorkshireman has been filled seamlessly by Ahmed.
Ahmed is England’s youngest senior male player in all three formats and has furthered his blossoming reputation against the Windies by recording identical figures of 10-1-40-2 in two ODIs in Antigua.
Livingstone believes he is getting the rub of the 19-year-old’s reliability after taking three wickets with his own spin on Wednesday, where England’s win set up a series decider in Barbados on Saturday.
“The flexibility that we’ve got – Rehan has obviously come in and replaced Rash, we don’t even know that Rash isn’t here,” Livingstone said.
“Rehan’s been incredible for us, he’s an exceptional talent we’ve got coming through.
“What one of our strengths has been for years is the depth we have, not only in our batting but our bowling as well. As a spin department we’ll be happy with (the win).”
With Rashid out of the side and Moeen Ali likely to become a T20 specialist, Livingstone is now one of the senior players in the set-up and is keen to take more responsibility.
“Mo and Rash have been incredibly supportive and helpful of me bowling over the last couple of years,” the 30-year-old said.
“I guess it’s my turn to kind of take that over from them and maybe try and help Rehan and (fellow spinner Will) Jacks along the way.”
By his own estimation, Livingstone is currently a bowler who bats rather than the other way around as his runs have dried up since ending the English summer with a flourish against New Zealand.
Following a sparkling unbeaten 95 at the Ageas Bowl in September, the Cumbrian has a top-score of 28 in his last nine innings, while he averaged a paltry 10 in six knocks during England’s miserable World Cup.
Asked to pinpoint where he might be going wrong, Livingstone said: “If I had the reason I’d have probably changed it by now. I keep turning up to training, trying as hard as I can.
“I guess maybe just try to put a little bit less pressure on myself and go out and enjoy myself like I have done my whole career. It only takes one innings to change it around.
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“I’ve had it before and I’m sure when things do change around, I’ll look back on this time in my career as something that was probably a massive learning curve for me.”
Even if he is in a trough with what first brought him into England’s limited-overs sides, Livingstone is happy to provide an increasingly useful option with the ball.
“Being able to affect the game and getting key wickets for us at key times, is probably a little bit more satisfying than getting runs at certain times,” Livingstone added.
With the three-match contest tied at 1-1, the hosts were bowled out for a disappointing 116 after being invited to bat first in the decider at Derby.
They never got to grips with Sri Lanka’s array of slower bowlers, with Chamari Athapaththu taking three for 21 and Udeshika Prabodhani and Kavisha Dilhari both claiming two wickets apiece.
Maia Bouchier top scored with 23 while Danielle Gibson added 21 late as England were skittled in the 19th over.
The innings could not have got off to a worse start as Danni Wyatt planted a gentle wide delivery from Inoshi Fernando straight to cover.
The Sri Lankans were celebrating again at the end of the second over when a calamitous mix-up between Bouchier and Alice Capsey saw both batters at the same end, with the latter ran out.
Bouchier and captain Heather Knight did some repair work, sharing a 30-run stand in four overs, but that came to an end when Bouchier holed out to long-on.
Knight (18) and Amy Jones (20) soon followed as England slipped to 72 for five in the 11th over and it looked like they would struggle to get to 100.
But Gibson hit three fours in her 15-ball innings to get them to three figures before a flurry of late wickets saw them fail to see out their overs.
