made his second century of the Royal London series to help England to a resounding victory over West Indies.
Bairstow, who was promoted to open the batting following a spell of poor form that saw Jason Roy dropped, followed his maiden ODI century at Old Trafford in the first match of this series with an accomplished innings of 141 from 114 balls. It was the highest ODI score by an England batsman in an ODI against West Indies and the first time an England player has scored two centuries in the same bilateral ODI series against them.
With the recalled Roy also taking his opportunity - he followed his innings of 84 at The Oval with an innings of 96 here - it suggested Alex Hales could face a prolonged period outside the team. Hales is not currently considered available for selection following a night out in Bristol.
The competition for places in the England squad is more intense than anything they experienced on the pitch at the Ageas Bowl. Set a modest 289 for victory, they eased to a nine-wicket win with an eye-watering 12 overs remaining. That sealed a 4-0 series win and stretched England's record against West Indies to 16 out of their last 17 ODIs.
While Roy and Bairstow's opening partnership of 156 in 21.2 overs will probably gain the plaudits after a disappointingly one-sided game, the key period arguably occurred much earlier. From the moment West Indies went more than 20 overs in mid-innings without hitting a boundary it became apparent they would set an inadequate total.
But for a brief flurry from Chris Gayle, when he thrashed 34 in six successive deliveries from Jake Ball, West Indies were oddly passive for much of their innings bat and allowed England's spinners - Man of the Series Moeen Ali and legspinner Adil Rashid - to bowl their 20 overs for a cost of just 78 runs. West Indies went from the final ball of the ninth over to the fifth ball of the 31st without hitting a boundary.
The day had started poorly for England. With Ben Stokes' immediate future uncertain, the importance of Chris Woakes to England has grown further. So it was far from ideal that he reported some stiffness in his lower back after the match at The Oval and was rested as a consequence. There are currently no plans for a scan but England will be anxiously monitoring his progress over the next few days.
In his place, Tom Curran came into the side for an ODI debut and produced a quietly impressive performance. Most notably, he demonstrated admirable skill and composure in producing a perfectly delivered back-of-the-hand slower ball to deceive and dismiss Gayle in full flow. It will prove a memorable maiden ODI wicket in a performance that may well have propelled him above Ball when it comes to future selection.
Ball found, like many before him, that bowling to Gayle in the Powerplay is no easy task. Despite starting with a maiden to Gayle, who didn't get off the mark until his 15th ball, the final three deliveries of Ball's third over were all thrashed - to say they were driven would hardly reflect the terrific force with which the ball was struck - for six by Gayle, while the first three of his fourth conceded two more sixes and a four to the same batsman. In all, Ball conceded six of the 10 sixes hit by West Indies during the innings.
Also deserving of credit for the Gayle dismissal was Liam Plunkett. Keeping his eye on the ball while running back from mid-off, Plunkett clung on to an outstanding diving catch to capitalise on Gayle's mistimed drive. A few overs later Plunkett took an equally good reaction chance off his own bowling - pouncing low and to his left, he clung on to a mistimed drive - to account for Kyle Hope, who came into the side in place of the injured Evin Lewis.
That wicket brought Shai Hope and Samuels together. And, while the pair were rarely troubled in adding 57, the fact that it took them 16 overs played into England's hands. Samuels's miserable series culminated in an innings of 32 from 60 balls with just one boundary and meant he finished the series averaging 15.25 at a strike-rate of 49.19. By the time he ran past one from Moeen Ali that slid on, it was hard to gauge whether it was England or West Indies supporters who were happier.
Shai Hope, at least, eventually found his form. Having not hit a boundary for the first 77 balls of his innings, he then hit three in succession as he started to anticipate Curran's variations.
Sunil Ambris, brought into the side in place of Jason Holder who returned to Barbados for the funeral of his uncle, also looked an accomplished, aggressive player. With Ashley Nurse, who hit 31 from 12 balls, he added some impetus at the end of the innings to partially compensate for the overs used up by Hope and Samuels. But, on another decent track, the West Indies total always looked a little short of par.
Not for a moment did Bairstow and Roy appear troubled. And, if it was the crisp striking that was a feature of the latter part of Bairstow's innings, it was his brilliant running between the wickets that left West Indies' stand-in captain, Jason Mohammed, scratching his head. Joe Root completed proceedings by hitting the final ball of the match for six and, in the process, becoming the third-fastest man in history to reach 4000 ODI runs.
The result completes the longest international season in England's history. In the 147 days since May 5, England have won 18 of the international games they have played (with one no-result), including Test and ODI series victories over South Africa and West Indies. All of which sounds excellent. But the failure to win the Champions Trophy and lingering fears for the future of Stokes cast significant shadows over those results.
West Indies, meanwhile, clearly have a great deal of work in front of them if they are to gain qualification to the World Cup.
George Dobell is a senior correspondent at ESPNcricinfo