Vroum Vroum Mag was made to pull out all the stops to justify prohibitive odds in the olbg.com Doncaster Mares' Hurdle.
Having claimed her third Grade One success in the Christmas Hurdle at Leopardstown last month, the Willie Mullins-trained eight-year-old was a 1-5 favourite to follow in the hoofprints of stable companion Annie Power, who won this prize 2014.
For much of the two-mile journey the race appeared to be going to script, with Vroum Vroum Mag seemingly travelling strongly under Paul Townend.
However, it was clear early in the home straight things might not be as straightforward as most expected, with Townend getting to work and Midnight Jazz going great guns in front.
Vroum Vroum Mag drew alongside at the final flight and looked set to go on, but Midnight Jazz would not go down without a fight and there was just a head between them at the line.
Townend said: "She got a good jump at the last and ground it out well, but I don't think it's her true run.
"On ratings you'd have expected her to do it a bit easier than that, but she's won, which I suppose is the main thing."
Vroum Mag holds six entries at the Cheltenham Festival including the Champion Hurdle, the Gold Cup and the Mares' Hurdle, which she won last season.
Joe Chambers, racing manager for owner Rich Ricci, said: "She got it done and toughed it out well. Paul said she just felt a bit flat.
"We'll get her home and see how she is and make a plan later on."