Salt came into the game after a record-breaking 141 not out against South Africa and put Ireland's bowlers to the sword as England chased down a total of 197 with more than two overs to spare.
The opener struck 10 fours and four sixes in his knock and was the key contributor but received good support from Jos Buttler (28), Sam Curran (27) and stand-in captain Jacob Bethell (24).
The home side's bowlers were up against it against the hard-hitting English batters but Matthew Humphreys (2-44) and Graham Hume (2-36) put in a decent shift in the defeat.
Earlier, Ireland thought they had a good total on the scoreboard when they reached 197-3 in their 20 overs after being put in to bat at the toss.
Harry Tector top-scored with an unbeaten 61 from 36 balls while Lorcan Tucker hit 55, also off 36 deliveries.
The hosts were given a decent start when opening pair Paul Stirling (34) and Ross Adair (26) put on 57 inside eight overs before spinner Liam Dawson (1-39) made the breakthrough for England.
The second match is due to be played in Dublin on Friday with the series concluding at the same venue on Sunday.
Australia took control of the second Ashes Test after the third day following a lower-order batting fightback and then taking six England wickets before the close of play.
Australia went to stumps on the second day of the pink ball Ashes Test on 378-6, the home side leading England by 44 runs on the first innings with four wickets still remaining.
Will Jacks is set to make his first Test appearance in almost three years after England named their starting XI for the second Ashes encounter against Australia that starts in Brisbane on Thursday.
England captain Ben Stokes has come out and said he will accept criticism for his team's performance in the first Ashes Test but has pushed back at jibes that the tourists are "arrogant".
