Hardy Eustace defended his Smurfit Champion Hurdle title in the showpiece race at Cheltenham on Tuesday.
The 7-2 joint favourite, trained by Dessie Hughes and ridden by Conor O'Dwyer, edged out Paul Carberry's mount Harchibald (7-1) by a head.
Hardy Eustace made all the running but looked set to be pipped by Harchibald before finding an extra gear.
Barry Cash and Brave Inca, sent off at 10-1, came in third to complete an Irish clean sweep.
Accordion Etoile finished fourth with Barry Geraghty on board Macs Joy in fifth.
O'Dwyer said: "I pinged the last and wasn't sure whether Paul's horse was going to pick up - I just wanted to get to the line.
"I can't describe it, I really can't."
Hughes, who won the race as a jockey on Monksfield in 1979, said: "I've never lost faith in him - he's a very good horse and he's improved. I can't believe I've won it again.
"I knew he was right for today. Looking around and seeing what he has beaten today, it has to be very possible that he could come back and make it three."
Harchibald's trainer Noel Meade was philosophical in defeat and was quick to praise Carberry's ride.
He said: "I watched the race with Dessie and I thought we had it won coming up the hill, but Paul said the other horse was the wrong one to come up against in that sort of situation.
"I was delighted with the ride Paul gave him. He gave him a brilliant ride and I could see the two of them coming back here next year.
"We thought beforehand that if we got to the front in the last 50 yards that would be ideal - if he had gone half a length up after the last I think the other horse would have come back and probably beaten him.
"The winner is a champion, and so is ours."
Brave Inca's trainer Colm Murphy was delighted with his horse's third-placed display.
"He has run a cracker and we are over the moon," said Murphy.
"He travelled well, jumped well and everything went to plan, but he just got beat. He has run a fast race for a second-season novice. "We will keep our options open for him, enter him at Punchestown and see what happens.
Graham Lee had a great start to the day on Arcalis
"As for next season we are spoilt for choice. We could go for the Champion again or go over fences for one of the two novices."
The 20-1 chance Arcalis gave big-spending Graham Wylie his first ever Cheltenham Festival victory in the Supreme Novices' Hurdle.
The multi-millionaire software and property tycoon has spent large amounts of money to achieve success and the horse also gave jockey Graham Lee his debut Festival win.
Howard Johnson's charge, who won last year's John Smith's Cup on the Flat at York showed a great turn of foot late on for the win.
"I'm more pleased for Graham and for Howard than myself," said the typically modest Wylie.
"They have both been working so hard for this. We bought Arcalis as a hurdler and he'll probably be a two-mile hurdler next season.
"I have made a big investment, but this is a great thrill and it was just stunning to watch the horse fly over the final flight.
"Graham gave him a fantastic ride and I can relax now and look forward to the rest of the week."
Connections of Contraband had to endure a nerve-wracking 15 minutes before the gelding was confirmed the winner of the Irish Independent Arkle Challenge Trophy.
The Martin Pipe-trained seven-year-old, ridden by Timmy Murphy, appeared to cross the second, Ashley Brook, on the run-in and after they flashed past the post an inquiry was quickly announced.
But after deliberating the matter, the stewards allowed the result to stand.
"I didn't like the inquiry going on a long time, but you've got to have luck on your side," Pipe said after the result was confirmed.
"He jumped well and travelled well. It's always a fast pace in the Arkle, which helped him settle, and the good ground helped as well.
"He jumped the last and the other horse didn't and that's what counted. It was a great ride by Timmy."