The deal that took Hart, 21, from his hometown club to Manchester City for £600,000 two years ago included an add-on for winning a full England cap.
And Hart won his first cap in the 3-0 win over Trinidad & Tobago, coming on as a half-time sub for David James.
Hart was signed for City by Stuart Pearce, his England Under-21s boss. He was an unused substitute in the play off final when the Shots lost in the penalty shoot out.
Thanks to his consistency between the sticks for City last season, the Shrewsbury-born keeper then caught the eye of senior England coach Fabio Capello.
But Hart is refusing to get carried away by his rise into the international ranks.
"Everyone just wants to be involved and play for their country," Hart told the FA website. "It's great looking back on how far I've come, but also how far there is still to go - and I won't take anything for granted."