Hannon, who won the Flat trainers’ championship in November, reached the milestone when Numeral, owned by Highclere Thoroughbred Racing, landed the 7f handicap at Lingfield yesterday at odds of 4-1 under apprentice Kieran O’Neill.
Johnston’s record, which he set in 2009, could be broken at Kempton today when Hannon saddles Silenzio in the 6f handicap.
Hannon landed the biggest success of his season with Canford Cliffs in the Group 1 Queen Anne Stakes at Royal Ascot in June.
Meanwhile, Frankie Dettori rolled back the years to win a third Cathay Pacific International Jockeys’ Championship in Hong Kong yesterday.
Not seen at the event since 2003, Dettori last won the appetiser to Sunday's Hong Kong International races at Sha Tin back in 2001 and was also victorious in 1999.
Yesterday’s win brings Dettori, who celebrates his 41st birthday next week, level with 11-time Hong Kong champion jockey Douglas Whyte as the most successful in the event's history.
Dettori started off with a win in the first leg aboard Travel Guide and picked up points when placed in the third heat but the event went right down to the final race of four, which he took courtesy of the Tony Cruz-trained Regency Winner.