Impervious caused something of a surprise when scoring at odds of 20/1 on debut in the Adare Manor Opportunity Maiden Hurdle at Cork.

The Colm Murphy-trained mare cost €26,000 as a three-year-old at the Derby Sale and showed that was money well spent with a decisive victory.

Mike O’Connor produced the daughter of Shantou to head 6/4 favourite Dark Spark before the final flight and she drew clear on the run-in to score by six and a half lengths. Fancy A Cosmo was a further five and a half lengths adrift in third.

O’Connor said, “The trainer filled me with plenty of confidence. He said to ride her mid-division and they went a nice gallop for the ground. She seems a nice mare going forward.”