Quevega completed back-to-back victories in the Ladbrokes.com World Series Hurdle at Punchestown with a narrow win over Mourad.
The two Willie Mullins-trained runners fought out the finish but it was Quevega, ridden by Ruby Walsh, who was too strong for her stablemate, ridden by Katie Walsh.
Carlito Brigante was a creditable third.
Luska Lad set the pace from Rigour Back Bob, who got rid of Andrew McNamara at the fifth flight, after which Carlito Brigante took closer order.
Quevega was never too far off the leaders and responded when asked to go and win her race.
Mourad came from further back and was never able to wear down the 8-11 favourite, who became the first favourite to oblige at the meeting.
Despite making a bad mistake at the last, the triple Cheltenham Festival winner still had a length and a quarter to spare over Mourad (11-2).
Mullins said: "She's an extraordinary mare for her size.
"She's just about 16 hands but as strong as an ox - I've never seen anything like she did at the last.
"To make a mistake like that and within two strides to be back up and running was pretty special.
"I thought she was gone or would throw Ruby off and he did very well to stay on her.
"Yet a stride after the mistake she was back up and running as though nothing had happened.
"I thought Mourad would go out by her, but he never got an inch on her up the straight.
"I can't see myself bothering to do anything else next year.
"Whether we go across to Paris for the French Champion Hurdle, that's the only other thing I have on my mind, or just wait for Cheltenham and come back here again.
"I'll probably enter her in the other races at Cheltenham but I have Mourad for the World Hurdle and we might have something else for that, too.
"I would say she'd run in the Mares' Hurdle again as, if you're lucky enough to have a favourite for a race at Cheltenham, you run in that race."