Approaching the second-last it appeared Style De Garde was beginning to paddle and Gumball looked set to take advantage, before the Nick Williams-trained Esprit De Somoza and Gary Moore's Aiguille Rouge, who had both been held up, came there full of running.
And it was Espirit De Somoza, having just his second start, who pulled five lengths clear of Gumball, who stayed on again.
Kelly said: "We went in there a little unconsidered, but I thought he was a really nice horse as the form of his Sandown race was pretty good as the winner (Sussex Ranger) has come out and finished second in a Grade One.
"I'm really pleased. I've not forced it, the front two were there to be beaten and I'm really pleased with the way he galloped home.
"He was not too spectacular down the back, but he just keeps galloping and can hurdle at that good two-mile pace and quicken off it, which is something rare for our horses as we don't have many precocious four-year-olds.
"He's very smart and professional and is almost workmanlike at home. I think they did go quite hard and they considered it a two-horse race, which it looked going into it, and they've slightly forgotten me."
She added: "It (Triumph Hurdle) is certainly in the notebook, he's a lovely horse."
Paddy Power introduced the winner into their Triumph Hurdle betting at 25-1 .