A daughter of the crack racemare Maybe Discreet, Too Darn Discreet broke the ice at start four with a brave performance in the Sportsbet Photo Finish Refund Maiden Plate (1500m) at Sandown-Hillside on Wednesday.
Ridden by Declan Bates for Dan O'Sullivan, Too Darn Discreet was made to work early following a tardy start.
After finding the perfect trailing spot, the Too Darn Hot (GB) found herself in front a long way out and looked cannon fodder for the fast finishers Vianarra, Oxford Blue, and Miss Playlounge.
Too Darn Discreet kept finding to repel the Shalaa (IRE) colt Vianarra by a neck with the Fiorente debutant Oxford Blue back in third.
"She was entitled to get beaten as she did a fair bit of work to get there, hit the front early, and wanted to lay in," O'Sullivan said.
"I thought they had her at the 100m, but she boxed on.
"There's a good motor there, and we have not seen the best of her yet. It will be interesting to hear what Dec has to say.
"I think she will get out to 2000m this time in."
Bred and part-owned by David Peacock, Too Darn Discreet is a half-sister to stakes-placed, 5-time winner Really Discreet (Helmet) and is the fourth winner from as many foals for the Shamardal mare Maybe Discreet.
A half-sister to Group III winner Just Discreet and stakes-placed Always Discreet, Maybe Discreet's four stakes wins were highlighted by the Group 1 SAJC Schweppes Oaks and Group II VRC Edward Manifold Stakes.
Maybe Discreet has a yearling brother to Too Darn Discreet and slipped to Ghaiyyath (IRE) last year.
