Amelia Glass was penalised for her ride on Lilbourne Star at Leicester on Thursday, after appearing to give up riding for a few strides effectively costing her chances of victory in the six furlong handicap at 5:25.
The apprentice has been hit with ten day ban after losing out by a neck to William Stone's Evening Attire, when very much shaping like the winner inside the final two furlongs of the nine-runner race.
The stewards reported after the race: "Glass was suspended for ten days for failing to take all reasonable and permissible measures to obtain the best possible placing on a horse that could have finished first."
Television replays showed the 7lb claimer - who was only allowed to claim three in the apprentice race, stopped riding for a few yards before actually realising the line had not yet come.
Glass - who has ridden seven winners in her short career to-date, glanced up to the big screen to notice there was still a race to run and finish but it was all too late on the four-year-old sprinter.
Trainer Clive Cox - who employs Glass, was not present at Leicester and was sad to hear the story when contacted later in the day.
(Credit: Racing Post) He said: "It was human error and Amelia is very upset and said she made a mistake and mistook the winning post.
"She is very hard-working and is a very able and progressive young rider.
"The mistake and ten-day ban is a strong enough punishment and will make sure she never forgets it."
Cox even admitted he was left unsure as to whether Lilbourne Star would have even won the contest aside from the jockey error.
He added: "He has not been the most straightforward horse to train and Amelia had given him a beautiful ride until making her mistake."
The female jockey has been riding for four years now, and got off the mark last season after just nine rides from her opening two seasons.
She completed the campaign with five winners from 30 rides - operating at a 16% strike rate, and has added a further two winners this year.
Mistakes happen with jockeys, and hopefully Glass can bounce back from this.