( CNN ) -- They think it 's all over ... it is now . Britain 's Queen Elizabeth II 's filly Estimate came tantalizing close to defending her Gold Cup title at Ascot only to be edged out by a neck by a fast-finishing Leading Light in one of the most thrilling finishes in Gold Cup history . A superb ride by Joseph O'Brien on Leading Light ensured that Estimate 's jockey , Ryan Moore , did not have things all his own way as they rounded the final bend . The two-and-half mile race came down to a sprint finish between Leading Light , Estimate , and Irish raider Missunited , who clung on to finish third , having made all the running . Also bidding to spoil to the royal party was Brown Panther , owned by former England footballer Michael Owen . He held on gamely to finish fourth . It 's not often you see two national treasures go head-to-head at Royal Ascot , but Owen himself is popular figure in the paddock these days , having enjoyed a successful second career as an owner and breeder . Day three of Ascot is also Ladies ' Day , which is always guaranteed to provide a glittering array of frocks and hats . The Queen herself , who was wearing blue , was gracious in defeat , presenting the trophy to the winning owners . `` It was tremendous and the Queen got such pleasure out of it. , '' said John Warren , her racing manager , of Estimate 's performance . `` To see her put in such a brave effort like that was tremendous . It was a career best . She ran as good as you could ever hope . '' Estimate 's trainer Sir Michael Stoute added : `` It was a great run and I 'm very proud of her . '' Missunited 's trainer Michael Winters was also pleased with his runner : `` She 's run her heart out and jockey Jim Crowley has given her a peach of a ride , '' he told reporters . `` There was a moment down the back straight when I thought she might have given them the slip but it was a super run and a great ride . '' Leading Light 's victory made it a double on the day for the O'Brien camp , as the trainer and his son had earlier opened their account with Bracelet in the Ribblesdale Stakes . Unusually , the 10/1 shot was the pair 's first winner of the week . `` We 're delighted to get a winner , '' conceded her trainer . `` She 's traveled and quickened well off a nice even pace , '' added her jockey . Earlier in the day , Baitha Alga struck in the Norfolk Stakes to give Frankie Dettori his 49th winner at the Royal Meeting . `` I 'm nearly there , '' exclaimed Dettori of his looming half century . `` It was a great performance . He 's hard as nails and uncomplicated - everything you want in a two-year-old . `` I just had to do the right thing , get into the race and use his turn of foot , '' added Dettori , who celebrated the win with his trademark flying dismount . There was another milestone for Stoute as victory for Cannock Chase in the Tercentenary Stakes gave the trainer his 70th Royal Ascot victory , making him the most successful living trainer at the meeting .
Leading Light wins thrilling Gold Cup . Queen Elizabeth II 's filly Estimate comes close to defending Gold Cup title . Day three of Ascot is also Ladies ' Day .