Aidan O'Brien received a welcome boost ahead of Galileo's Derby bid when Dietrich got up close home to capture the Group 3 Ballyogan Stakes at a wintry Leopardstown.
Favourite Final Exam looked set to score when taking it up from Inourhearts over a furlong out, but had no answer when Michael Kinane delivered his late challenge.
'She has always been very fast, and we thought she was very good last year but she seemed to go wrong,' said O'Brien, who is now likely to aim the filly at the King's Stand Stakes.
One Won One recorded his first success over 1m, and his ninth in all, when coming from off the pace to take the Listed Glencairn Stakes under Eddie Ahern.
The seven year-old swept past market rivals Bach and Tarry Flynn inside the last, and Ahern could even afford the luxury of easing his mount close home.
Trainer Joanna Morgan believes her charge is better than ever since returning from a spell in Dubai, and will probably bring him back to Leopardstown for the Group 3 Ballycorus Stakes next Wednesday.
Just Special may be Royal Ascot-bound following a stylish success in the opening 7f maiden, sprinting clear inside the closing stages to score by five lengths.
'She's in the Cork and Orrery, and I think she has enough pace to run in that, but she is quite delicate,' said handler Michael Grassick.
'We'll have to see how she comes out of this, but there is also a 7f race for her at the Curragh on Derby weekend,' he continued of his winner, who was initiating a brace for Eddie Ahern..
Sahara Slew showed tremendous courage to resist the strong challenge of Beyond The Pole in the 1m4f maiden and earn a possible tilt at the Ribblesdale Stakes.
Just a short-head separated the pair at the line after a thrilling duel, and John Oxx is hopeful that his 'tough, honest' filly will continue to go the right way.
Sheer Tenby stayed on strongly to follow up his Killarney victory and give Michael Kinane a double in the 1m1f handicap, while bottom-weight Richie Rich turned Div. 1 of the 7f handicap into a procession under Mary Williamson.
Ciara Flyer just got the better of Gers Gold by 3/4 length in Div. 2, before Direct Bearing came out best in a three-way tussle as the 1m6f QR Race produced another tight finish.
