Apprentice jockey Jacob Opperman was the talk of Adelaide town on Saturday evening after he managed to steer home five winners at the Morphettville Parks meeting in South Australia.

Having not had a ride in the opening event on the day, the 17-year-old went on to win with each of his first five rides on the card.

After winning on Royal Obsession, Jaguary, Icecrusher and Imperial Hilton, Opperman had to watch the sixth race from the jockeys' room after his mount Picargo was scratched.

He did not have to wait long to back into the winner's stall, however, steering home Greetings Ned in the second leg of the quaddie.

It remains unknown if Opperman's stretch of five winners in a row is a record for an apprentice jockey at a metropolitan meeting, but it would surprise no one if he was the first to do so.

Having only begun his career a little over 12 months ago, Opperman has ridden 83 winners from 569 rides, including 22 victories from just 101 rides at metropolitan meetings.

With the handful of winners on Saturday, Opperman had his weight claims slashed within the space of six hours. His allowance for metro meetings was reduced from 3kg to 2kg, and down to 1.5kg for provincial races, while he can no longer claim any weight in country gallops.

It was a great day for apprentices at Morphettville, with Sophie Logan booting home the $31 roughie Madam Furphy in the opening race, before Queensland-based Madeleine Wishart rounded out the card with a win aboard Midnight Storm for Leon Macdonald & Andrew Gluyas.

Elsewhere, Reece Jones and Alysha Collett had field days at their respective meetings in New South Wales. Jones managed to steer home four winners at Randwick, whilst Collett bagged five winners at Newcastle.