The Paparrazi Kid upstaged stable companion Felix Yonger in the feature Greenmount Park Novice Chase at Limerick.
Felix Yonger was a warm order for the Grade Two contest having won his first three starts over fences, and was sent off the 2-5 favourite in the hands of Paul Townend.
However, 5-1 shot The Paparrazi Kid jumped smartly in the hands of Emmet Mullins and was ultimately well on top as he held off Felix Yonger by a length and a half.
Balnaslow was four lengths back in third to give Willie Mullins, who endured a largely disappointing day at Leopardstown, a one-two-three.
Speaking after racing at Leopardstown, Mullins said: "The Paparrazi Kid did nothing wrong. It probably wouldn't have been Felix Yonger's ground, but he had a lot of ground to make up."
Emmet Mullins said: "I fancied The Paparrazi Kid to finish second to Felix Yonger and knew that if things didn't go right for him, I'd have a chance.
"It wasn't the plan to make the running but he winged the first and landed in front. He was electric everywhere and I was able to fill him up turning in. He is improving all the time and loves that ground."
The Paparrazi Kidcompleted a big-race double on the card for the champion trainer, with Townend steering Smashing to a clear-cut victory in the O'Kelly Bros. Demolition & Environmental Contracts Hurdle
Willie Mullins said: "Smashing was very good. He jumped huge and gave his hurdles a foot or more, which tells me there was a lot more in the tank. He's a lot better than we were even hoping."