Hurricane Fly won the Irish Champion Hurdle at Leopardstown from Solwhit.
The Paul Townend-ridden winner, trained by Willie Mullins, was securing his fourth victory over his old rival, who has won one of their encounters.
Sent off a 4-9 favourite, Hurricane Fly won by three-and-a-half lengths and is one of leading players for the Champion Hurdle at Cheltenham on 15 March.
Earlier, the Noel Meade-trained Realt Dubh (5-2) beat Noble Prince by a short head to win the Irish Arkle Chase.
In the big hurdle race, Thousand Stars had set the pace.
Solwhit (3-1) tried to challenge approaching the final flight but he had to settle for second best again.
County Hurdle winner Thousand Stars was third, with Voler La Vedette fourth and 2007 champion hurdler Sublimity last of the five runners.
The 2010 winner Binocular remains a general 3-1 favourite for the Champion Hurdle, with Hurricane Fly about 7-2 ahead of 5-1 shots Menorah and Peddlers Cross.
Hurricane Fly has missed the last two Cheltenham Festivals through injury, and Mullins is hoping he will make this year's meeting.
"I think he'll go straight to Cheltenham now. I haven't any other plans for him. I'm delighted to get that over," said the champion Irish trainer.
"It's our first Irish Champion Hurdle success so I'm going to enjoy it."