Adil Rashid showed he has learned from a “tough” winter by taking 5-27 to help England beat Ireland by seven wickets in Bristol, said captain Eoin Morgan.
Leg-spinner Rashid, 29, struggled for consistency as England lost a Test series in India 4-0 late last year.
He was dropped after the first one-dayer against India but performed well in the West Indies series in March.
“He’s a huge asset for us and hopefully he gets it right in the middle of the summer,” said Morgan.
Rashid’s figures on Friday were the second best by an English spinner in one-day internationals, behind the 5-20 taken by Vic Marks against New Zealand in Wellington in 1984.
“It was a tough time in the winter and he’s clearly learned from it,” Morgan told BBC Test Match Special. “He’s slowly building back enough confidence.
“Coming out with his career-best performance after having a very tough winter in India and starting to put something together in the West Indies – it shows the threat leg-spin has.”
England play the second and final one-dayer against Ireland at Lord’s on Sunday (11:00 BST).