Lachlan King couldn't wipe the smile from his face after Sherlock Holmes gave the apprentice a maiden victory at Flemington.

The son of Melbourne Cup-winning jockey Steven King, Lachlan had previously tasted city success at Mornington.

Carrying the colours of Lloyd and Nick Williams, Sherlock Holmes outplugged his rivals to take out the Living Legend Efficient Handicap on Saturday.

Efficient, owned by Lloyd Williams, is one of his six Melbourne Cup winners.

Sent off a $4.80 chance, Sherlock Holmes scored by a length from Charlevoix ($9) with Sly Romance ($31) a half-length away third.

"As I crossed the line you can probably see by the look on my face that I was pretty happy with myself," King said.

"It was probably more important that I got it for Lloyd Williams, one of the biggest owners, to get the ball rolling and get my name out there.

"Dad does a lot of work up at Macedon Lodge and so it worked out really well."

King said he had been trying too hard to get his first Flemington winner out of the way.

His father told him to relax and to get the basics right.

"I was probably riding a bit rushed before, making little mistakes," King said.

Sin To Win lost jockey Cory Parish 200m after the start before racing around the field.

King said that helped put some tempo into the race.

"Even though it's a horrible thing, and I hope Cory is alright, it actually worked in our favour," King said.

Parish was taken to Epworth Hospital for observation, complaining of lower back soreness.

As the race had to go past where Parish fell, Racing Victoria stewards were ready to direct the remaining runners around the fallen jockey.

Luckily Parish was able to get to his feet and he was moved inside the running rail.

"I had my finger on the button ready to call it off," chief steward Terry Bailey said.