Sanderson (19) partnered Da Ginstar, who overcame a second line draw over 2200m (mobile) at Invercargill.
Sanderson, who had two drives at trials last season, is employed by Kirk Larsen, the trainer of Da Ginstar.
Sanderson started working for the stable when he was at school three years ago.
Da Ginstar was having his second start for the Larsen stable.
The 5yr-old son of Christian Cullen joined the stable during the winter after being gelded.
Da Ginstar won at 2 and 3 from nine starts when trained by Laurence Hanrahan.
Regina Coeli, a winner for the stable in 1.59.4 at Winton on Sunday, has been entered for a heat of the Sires' Stakes for 3yr-old fillies at Forbury Park on Sunday.
The Larsen-trained The Showman is in a heat of the Sires' Stakes for colts and geldings at Addington on Friday night.
The Christian Cullen colt won his last start at Ascot Park on October 3.
Report For Duty won a workout at Ashburton yesterday in 3.01.3 for 2400m, the last 800m in 55.8.
He started from 30m.
He is entered for the Ashburton Flying Stakes on Monday.
He finished last when favourite at his last start on October 3.
He was found to have a trace of blood on a nostril when inspected by a veterinarian after the race but he was not deemed a bleeder.
His trainers, Tim Butt and Phil Anderson, won with Bachelorette, Stunin Cullen, Cullen's Creek and The Force at Addington last Friday night.
The last three are in the Sires' Stakes heat this Friday.
David Butt has the drive on Cullen's Creek.
Mountbatten, a stablemate, won his workout yesterday in 3.05.3, the last 800m in 58.
He is in the feature mile at Ashburton.
Jimbob Jac is the backmarker on 60m in the Tuapeka Cup at Forbury Park on Sunday.
He has won at Forbury Park and Invercargill in two starts in a fresh campaign.
