Cox had not been named in the initial squad for this series and was added only after his starring role for the Oval Invincibles in The Hundred, where he was the leading run-scorer and named Most Valuable Player.
One of two changes from Wednesday’s win, his return to the starting side represented his first international outing since November and a first T20 for England in over a year.
Injuries cost him his Test debut in the intervening months, first against New Zealand last winter and then against Zimbabwe in May.
After appearing to injure his knee when making the catch for the wicket of Ross Adair, there was a time on Sunday afternoon when it appeared luck was to be against him again.
However, Cox said afterwards: “There was no chance I wasn’t going to bat because I might have to wait for another two years.
“Getting into this team is pretty tough. Hopefully it will be fine but I don’t actually know as I’ve not seen physio yet.
“I’m not going to let the opportunity to play for my country go because I’ve got a sore knee. Just deal with it, battle on.”
Fit to bat, Cox came to the crease at a time when England had failed to make the authoritative start they would have sought in their reply.
After their chase was delayed by rain in between innings, they were 57-2 after the powerplay. Brilliant catches from Curtis Campher and Delany accounted for the wickets of Jos Buttler and Jacob Bethell respectively, the former for a two-ball duck.
However, Cox steadied the ship. Occasionally hobbling between the wickets, he sprinkled eight boundaries, including a six over the grandstand, through a professional innings that took the game away from Ireland before he was bowled by Ben White for 55.