The Irish 32-year-old showjumped clear on Fenyas Elegance to hold her cross-country lead of 1.5pen over Frenchman Jean Teulere.
“This means a huge amount. She’s been a star this week, and is at just the right age to be looking at the World Equestrian Games and Rio [2016 Olympic Games],” said Aoife.
The 9-year-old chestnut mare, owned and bred by PJ Hegarty, added just 4 cross-country time-faults to her dressage score of 40 throughout the weekend.
Jean Teulere is aiming for another slot on the French team next year with Matelot Du Grand Val, who showjumped clear for 2nd place.
And America’s Clark Montgomery, also clear for 3rd place with Loughan Glen, is another with the world championships in France next year in his sights.
“I’m really happy with him — we just need to get a little bit better!” said Clark, who is based at Christian Landolt’s Tetbury yard.
The highest placed British rider is Gemma Tattersall, 4th on Arctic Soul. The pair were also the only ones to come home inside the time allowed on the cross-country, rising from 22nd place after dressage. They had a single pole down in the final phase.
She was followed home by Richard Jones and Highland Ford, who also brushed one pole for 5th place.
William Fox-Pitt held on to his lead in the 8/9yo CIC*** on Fernhill Pimms, really putting his foot down in the final cross-country phase to come home 1sec over the time.
Dressage leaders Christopher Burton and Graf Liberty had dropped to 2nd with a showjump down, but were the only pair of the class to make the time across country and retained that position.
Cross-country time-penalties decided the placings in this class, with Mark Todd and Leonidas II rising from 5th to 3rd with 2 time-faults.
Bill Levett and Improvise came up from 6th to 4th, while Paul Tapner and Indian Mill made amends for 2 showjumps down with a speedy cross-country for 1.2 time-faults and 5th place.
Read full magazine report from Fidelity Blenheim International Horse Trials in Horse & Hound, on sale Thursday 19 September
Blenheim Horse Trials final results CCI***
1. Fenyas Elegance (Aoife Clark, IRE) 44
2. Matelot Du Grand Val (Jean Teulere, FRA) 45.5
3. Loughan Glen (Clark Montgomery, USA) 45.5
4. Arctic Soul (Gemma Tattersall, GBR) 52.5
5. Highland Ford (Richard Jones, GBR) 53.8
6. Faerie Dianimo (Jonelle Richards, NZL) 58.6
7. Grand Manoeuvre (Nick Gauntlett, GBR) 61.8
8. Gryffindor (Kai Ruder, GER) 63.3
9. Xam (Harry Dzenis, GBR) 66.1
10. Pavarotti (Jessica Phoenix, CAN) 69.7
Blenheim Horse Trials final result 8/9yo CIC***
1. Fernhill Pimms (William Fox-Pitt, GBR) 33.5
2. Graf Liberty (Christopher Burton, AUS) 36.9
3. Leonidas II (Mark Todd, NZL) 44
4. Improvise (Bill Levett, AUS) 45.7
5. Indian Mill (Paul Tapner, AUS) 46.9
6. Amazing VIII (Flora Harris, GBR) 49
7. Belcam Bear (Emma Dougall, AUS) 49.8
8. Fernhill Quality Street (Kevin McNab, AUS) 51.2
9. Zebedee De Foja (Olivia Wilmot, GBR) 57.1
10. Stonedge (Nicky Roncoroni, GBR) 57.2