Sam James enjoyed his biggest day in the saddle, with Poptronic all heart to deliver a surprise victory in the Qipco British Champions Fillies & Mares Stakes at Ascot.

A winner of the Lancashire Oaks earlier in the season, Karl Burke’s four-year-old was sent off at an unfancied 22-1 after disappointing in Group One company the last twice.

However, she showed her quality on British Champions Day and having been to the fore throughout in the hands of James – who was striking at Group One level for the first time – she had plenty in the tank as those from a positions further back presented a stern challenge in the closing stages.

Both eventual second Bluestocking and the 3-1 favourite Jackie Oh in third stayed on stoutly to push Poptronic all the way inside the final half-furlong, but they could not get by the gutsy northern raider, who finished a neck clear at the winning post. Frankie Dettori had to settle for fifth place with Free Wind.