The 37-year-old seamer, born in London but qualified for Ireland through his grandparents, has spent much of his career with Lord's based-Middlesex, whom he joined from London rivals Surrey in 2007.
And having recently taken his 800th first-class wicket, Murtagh enjoyed a remarkable return of five wickets for 13 runs in nine overs on the opening day of Ireland's first Test match clash with England and just their third in all.
Murtagh, far from express pace with his quickest deliveries around the 75 mph mark, proved too much for a succession of England batsmen as he cut the ball both ways off a green-tinged pitch.
The tailender also hit a boundary off Stuart Broad to give the visitors a first-innings lead of over 100 runs as their jubilant supporters belted out traditional Irish songs such as the 'Fields of Athenry' and 'Molly Malone' at a ground known more for cathedral-like calm and polite applause.
Ireland were eventually bowled out for 207, a first-innings lead of 122 runs, with England - who only 10 days earlier won the one-day World Cup at Lord's - negotiating a Murtagh maiden to reach stumps on nought for nought second time around.
Prior to this match, Murtagh had taken 291 wickets at Lord's but this return meant he got his name on the honours board recording all those who have taken five or more wickets in a Test innings at the 'home of cricket'.
"As a kid growing up I dreamt of being on that honours board, probably not in the away dressing room -- but that makes it even more special,” Murtagh told reporters after stumps.
"It's as special as it gets for a cricketer...It's as good a feeling as I've had in my career."
Murtagh jokingly added: "I'm a bit long in the tooth but I should know how to bowl here!"
England captain Joe Root had insisted beforehand that he did not want his side "sleepwalking" into a match that came so soon after their World Cup triumph and just over a week before they begin a five-Test Ashes series.
While England rested World Cup-winners Ben Stokes and Jos Buttler from this match, several members of the team that just edged out New Zealand in a thrilling final were involved.
- 'No real excuses' -
But none of them made double figures, with Test debutant opener Jason Roy out for five and Root falling for two, while Jonny Bairstow and Chris Woakes were both dismissed for ducks, with the other nought in England's innings colleted by Moeen Ali - a World Cup squad member but left out of the XI that played the final.
"You'd probably say there aren't too many sports where you win a World Cup and are playing again a week later," said England batting coach Graham Thorpe.
"But it's a balancing act with the Ashes coming up.
"I don't think you can bury your head in the sand. The schedule is what it is and we have to do our best to give the players the opportunities to put them in the best place to start an Ashes series, which is an important part of an already exciting summer."
However, former England batsman Thorpe insisted: "There's no real excuses for us being bowled out for 85 against Ireland but congratulations to them, they put us under pressure and didn't let us off."