He first discovered Omaha and Texas hold'em on a weekend trip to a Dublin casino at the age of 22.

He defeated the largest field ever assembled for a European poker tournament when in 2007, he won the €3,300 buy-in event in Dublin.

Smyth eventually defeated Roland De Wolfe in a heads-up encounter Terry Rogers Memorial Trophy and earning €650,000.

On the final hand on a board of Q♣ 9♥ 10♣, Smyth made a pot-size bet of 600,000 holding K♣ J♣ J♠ Q♦ holding a made king-high straight, his opponent Peter Jetten re-raised pot, Smyth then re-raised all-in and was call by Jetten who was holding K♠ J♦ 3♦ 2♣ for the same king-high straight, however Smyth was freerolling on the re-draw to a flush as well as an open-ended straight flush draw, both the King high and the Royal Flush, the turn was a blank, the 7♦, but the river brought the 6♣ giving Smyth the winning flush and the Championship.

[5] Marty considers his bracelet win to be his biggest achievement, but highlights the Irish Open title as his most "life-changing".