Eoin Morgan congratulated Adil Rashid on bouncing back from his "tough winter" after the leg-spinner's maiden five-wicket haul set England on the fast track to victory over Ireland.
Rashid's 5-27 helped to dismiss Ireland for 126 in 33 overs, in their first game in England, before Alex Hales (55) and Joe Root (49no) were the driving forces as the hosts completed the chase in just 20 overs for the loss of three wickets.
Rashid paid a heavy cost for his 23 wickets in England's Test series defeat before Christmas against India, whose batsmen are so formidable in home conditions.
But he was back to his best with the white ball as Morgan's men opened their high-profile summer by charging to an early victory to go 1-0 up in the two-match Royal London Series. The final match takes place on Sunday at Lord's.
Morgan said: "It was Adil's day. I thought he put in a magnificent effort with the ball.
"He had a tough winter and has learned a huge amount to come back with confidence to bowl his variations and show how threatening he can be."
Rashid's ODI career-best has been bettered only once by any England spinner - Vic Marks in 1984.
Asked how highly he rated his spell himself, the Yorkshireman said: "It was probably up there - I've had a couple of other performances as well. I hope I can now carry it on into the summer."
Profiting mainly with his very effective googly, he had three lbw victims and also clean-bowled left-hander Stuart Thompson.
"You have good days and bad days - it's how you deal with it," Rashid added.
"Sometimes you don't feel great, and you've got to find a Plan B or even C ... it's a learning curve."
As for his success with the googly, a theme of many of his limited-overs successes in recent times, he said: "It all depends on the day.
"Some days you feel great, the googlies come out pretty hard to pick; some days they don't.
"When it doesn't I stick to the sliders or leg-spinners ... but some days it comes out exceptionally well, and then I have the confidence to bowl them."
England preferred Rashid as the only spinner, because the dimensions of the Bristol ground meant Morgan did not feel he could bowl him and Moeen Ali together.
It transpired he was able to deploy Root's part-time off-breaks, however.
"Bowling spin in tandem just wasn't an option, and we went for Adil because we thought he'd be a bigger threat on this wicket," said Morgan, who acknowledged Root remains a handy alternative as a second-string. "Yes, potentially he is.
"I think you find a lot of teams we come up against under-estimate Joe [as a bowler], and using him has worked for us - probably more so in Twenty20 cricket."
Morgan was also heartened by the returns of all four of his seamers after recent injuries, most notably Mark Wood following his well-chronicled struggles with his left ankle.
After the success against his compatriots, the Irishman said: "We probably started out a bit rustier than we'd like but looking back on it, I think the wicket was beautiful to bat on.
"When you look at today, and what you're trying to get out of it, it was number one the result and then number two getting our bowlers some overs in.
"That didn't happen quite the way we'd like, but that's the way the game went. I couldn't have asked any more from the boys today."
Reflecting on his team's most disappointing performance, Ireland captain William Porterfield said: "I'd never use the phrase out of (our) depth.
"I think we started off pretty positively ... (and) wouldn't necessarily have envisaged that spin would do the damage.
"Not taking anything away from Rashid, we should have played it a lot better. That's something we need to mentally put right for Sunday."
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