Simi Singh said "everything clicked with bat and ball" as his bowling figures of 5-10 and unbeaten 54 helped Ireland defeat the United Arab Emirates in the one-day contest in Abu Dhabi.
The win secured a 1-1 draw in an ODI series originally scheduled to last four games but reduced to two because of Covid-19 cases in the UAE squad.
"I'm absolutely delighted with the win and my personal performance," he said.
Captain Andrew Balbirnie described Singh's bowling as "exceptional".
Balbirnie and the Ireland management left Singh out of the team for the series opener on 8 January when the hosts clinched a six-wicket win.
'Who didn't pick Simi in the first game?'
The captain, in a self-deprecating fashion, admitted it appeared the wrong call in the light of Monday's game.
"Dunno who didn't pick Simi in the first game... they should definitely take a look at that," he joked.
Singh, 33, was born in India but has lived in Ireland since arriving as a student 16 years ago and made his debut for his adopted country in 2017.
His bowling figures in Monday's game were the third best five-for tally in ODI cricket this century with only India's Stuart Binny, with 6-4 against Bangladesh in 2014, and Sri Lankan legend Muttiah Muralitharan, taking 5-9 against New Zealand in 2002, producing more economical displays with the ball.
"The bowling plan was quite simple just to bowl as many dots as I could," said Singh.
The all-rounder said his earlier batting display - as his unbeaten 54 helped Ireland regroup from 10-3 to post a competitive 228-6 - had boosted his morale before taking on his bowling duties.
"Definitely the momentum from the batting just carried on with the bowling," he said.
"I got a couple of wickets early and just found a good rhythm and luckily got the five wickets."
Singh deserves 'all the plaudits' - Balbirnie
However, Balbirnie said Singh deserved "all the plaudits" for his display.
"For Simi to come into the game, not having played in the first one, and bowl with that control was exceptional," added the Ireland captain.
"The control, the accuracy and the wicket-taking ability, it was an absolute joy to watch him in full flow."
Singh's earlier innings was arguably just as important in keeping Ireland's chances alive in their final match before their three-game World Cup qualifier series against Afghanistan, which starts in Abu Dhabi on Thursday.
Balbirnie and experienced openers Kevin O'Brien and Paul Stirling departed cheaply to leave Ireland reeling on 10-3 before Harry Tector and Lorcan Tucker steadied the innings with a 72-partnership.
They departed in quick succession to leave the Irish on 99-5 before Singh and Curtis Campher (56) hit half centuries to give the visitors something to bowl at.
"Losing three quick wickets and the top three was a big setback but the way Lorcan and Harry dug in there and got through the tricky period on a very tough wicket this morning was brilliant," added Balbirnie.
"It set us up so that Simi and Curtis could come in and play the knocks that they did. Curtis played with great intent from the off and Simi built his innings up beautifully so to get to close to 230 was brilliant from where we were.
"It just showed we had that depth in the middle order to get us out of a hole."