Opie Bosson will turn the clock back on Saturday with a dozen mounts at Matamata, including three in black type events and an unexpected opportunity to add to his Group One tally.

Eleven of his 12 mounts on the extended card will be in his role as retained rider for Te Akau trainer Mark Walker with star mare Imperatriz to potentially provide the highlight for the pair.

The daughter of I Am Invincible wasn’t originally in the field for the Gr.1 Arrowfield Stud Plate (1600m) at Hastings last weekend, but the abandonment of that meeting and rescheduled change of venue has her back in the running.

Bosson, 42, is in grand form and currently leads the Jockey’s Premiership with 22 winners as he fronts up at Matamata for his busiest day in the saddle for decades.

“I don’t think I would have had this many rides since I was a teenager in Singapore,” he said.

Imperatriz will be heavily favoured to claim top honours in take two of the Arrowfield Stud Plate and edge Bosson one closer off his current mark of 87 to a century of Group One victories.

She was a runaway winner at Te Rapa when resuming the Gr.2 Foxbridge Plate (1200m) before she found the heavy ground too testing at Hastings when fourth in the Gr.1 Tarzino Trophy (1400m).

“I galloped her on Tuesday morning and she worked super, she was her normal self. I’m expecting a big run from her, but it’s not over until the job is done and better ground would be ideal for her,” Bosson said.

He will also be aboard market fancy Dynastic in the Gr.2 AHD Hawke’s Bay Guineas (1400m), who was an impressive first-up winner of the Listed El Roca – Sir Colin Meads Trophy (1200m) in his seasonal return.

“He wasn’t that comfortable in the ground and it was a good, tough effort and he’s gone the right way since,” Bosson said.

“He’s a happy horse and has worked nicely so hopefully it’s onwards and upwards with him.”

Dynastic is the $3.80 favourite for next month’s Gr.1 Al Basti Equiworld Dubai New Zealand 2000 Guineas (1600m) while Stella Splendida is currently the most favoured at $8 of the stable’s Gr.1 Barneswood Farm New Zealand 1000 Guineas (1600m) contenders.

A stylish debut winner at Taupo, she will be partnered by Bosson in Saturday’s Comag Ltd 3YO (1400m).

“I will be riding her a kilo over at 56kg. She is a smart filly, she’s still learning and I’ve got a lot of time for her,” he said.

However, Bosson has yet to commit to a 1000 Guineas ride with Tivaci’s daughter One Kiss also high on his list having guided the Walker-trained filly to an impressive last-start win in the Listed Canterbury Belle Stakes (1200m).

“One Kiss won really well last start and she’s thriving down there at Riccarton so there’s a couple more runs yet to work it all out,” he said.

Bosson’s other black type ride on Saturday is the in-form Perfect Scenario in the Listed Team Wealleans Matamata Cup (1600m).

His book for Walker also includes Elounda (race one), I’m Not Bossy (race two), Wild Night (race three), Outfit (race four), Supreme Khan (race eight), Leaderboard (race 10) and Fierce Flight (race 12) while he will combine with Novak for Clinton Isdale in the penultimate event.