Jordan Cox has struggled for luck in his brief international career. A broken thumb denied him a Test debut against New Zealand last winter; an abdominal injury forced him out of the squad to face Zimbabwe at the start of this summer. And after England bowled first in the final T20 international against Ireland, he jarred a knee while taking a catch in the deep, forcing him off the field and bringing into question what role he would play in the chase.

But a grimacing knock was also a breakthrough: Cox struck a 35-ball 55, his first international half-century, in a chase of 155, securing England a comfy six-wicket victory and a 2-0 series win. Having entered at 33 for two, the 24-year-old – who was not originally included in the touring party – was tested in an experimental middle order and reeled off the strokes that made him the leading run-scorer in this year’s Hundred. Tom Banton showed calm, too, putting on 49 with Cox and remaining unbeaten on 37.

“I seem to do well in an Oval [Invincibles] shirt,” said Cox. “So I was like: ‘Come on, this is just franchise cricket and I’m playing for the Oval, so just enjoy it and have a bit of fun.’ To get in this team is pretty tough. There wasn’t a chance I wasn’t going to bat because I might have to wait another two years.”

Rain got in the way of the second T20, and while winter jackets were still required, Malahide found some sun in the early afternoon. England made two changes: in came Cox and Sonny Baker, who made his second white-ball bow this month. The first had been ruined by Aiden Markram’s bat as Baker conceded 76 from his seven overs on his one-day international debut.

Ross Adair’s record is some way off Markram’s, but the 31-year-old quirky method – the backlift set up for cross-bat bludgeons – enjoyed Baker’s opening spell. The quick’s second over went for 16 as Adair lofted the ball over the off-side ring.

Spin brought England joy. Liam Dawson took two deliveries to find Paul Stirling’s edge, while Rehan Ahmed had Adair sweeping to deep midwicket, gone for 33 off 23. Harry Tector and Lorcan Tucker combined for 123 in the opening T20 but there was less stability in the middle order this time round. Jamie Overton prompted a couple of miscues, while Ireland failed to decode Adil Rashid’s googly.

The game, however, refused to go Baker’s way: Gareth Delany picked a slower ball to drive through the covers for four and back-to-back sixes behind square leg followed, the seamer’s threat reduced whenever he dropped short. He finished with figures of none for 52 from four overs. Brighter days will hopefully follow but the shift from domestic cricket has been brutal.

Passing showers delayed the restart before Jos Buttler fell for none to a ludicrous catch by Curtis Campher at short cover, flying low to his right for the one-hander. Cox, who hurt himself at deep backward square when holding on for Rashid’s third wicket, settled quickly after Bethell departed at the start of the fifth over. He swung hard over the leg side and moved to 22 off just eight deliveries.

But he looked in pain, too, when jogging down the pitch to close the powerplay with England 57 for two, his hand on the troublesome knee. “It was definitely sore, but I did it in the Hundred. I haven’t played since the Hundred final, resting my rib for four weeks, but I also had a bit of a sore knee then. I’m not going to let down the opportunity to play for your country because I’ve got a sore knee.”

Phil Salt swapped his usual hyper-aggression for a more measured approach at the other end, and while he edged behind off Campher for a 23-ball 29, England’s required rate was below six as they entered the final 10 overs. Cox eventually succumbed to Ben White’s legspin, but he had already decided the game’s direction.