She won the Railway Stakes (1200m) and BCD Group Sprint (1400m) in New Zealand before taking all before her in Australia after Te Akau set up base at Cranbourne in Victoria.
Her final 10 starts were in Australia and included six Group 1 wins, a Group 2 win in the McEwen Stakes, a gallant Yulong Newmarket Handicap second placing under 58kg and last Saturday's fourth placing in the Group 1 T J Smith Stakes.
She twice won the William Reid Stakes (1200m) at The Valley, where she also won the Moir Stakes (1000m) and Manikato Stakes (1200m), while she won a Black Caviar Lightning (1000m) and Darley Champions Sprint (1200m) at Flemington.
"Imperatriz was simply an incredible racehorse," Walker said.
"Her determination and will to win was supreme. She has been remarkable flagbearer for Te Akau's new Australian stable and we will be forever indebted to her.
"It has been such a privilege to train 'Berri', and she's been an absolute pleasure by every measure."
The news of Imperatriz's retirement came just hours after the horse who beat her home in the Group 1 Yulong Newmarket Handicap, James Cummings-trained colt Cylinder, was retired to stand at Darley's Northwood Stud in Victoria.
Leigh Jordon, VRC Executive General Manager – Racing was equally as complimentary of the mare.
"We feel very honoured and privileged to have had Imperatriz race at Flemington. She provided memorable moments and we loved seeing the tangerine silks first past the post in two of our highest-rated Group 1 sprints.
"We look forward to following her when she commences broodmare duties and hopefully she can pass on her speed, determination to win along with beautiful looks and nature to all her foals."
IMPERATRIZ
5YO Bay or Brown Mare
Sire: I AM Invincible
Dam: Berimbau (Shamardal (USA))
Trainers: Jamie Richards (2020-2022), Mark Walker (2022-2024)
Owners: Te Akau Empress No.1, Te Akau Empress No.2
Career: 27-19:3:1
Prizemoney: $6,969,799
Flemington highlights:
1st 2023 Group 1 Darley Champions Sprint (1200m)
1st 2024 Group 1 Black Caviar Lightning (1000m)
2nd 2024 Group 1 Yulong Newmarket Handicap (1200m)
Other career Group 1 highlights:
1st 2022 Group 1 Levin Classic (1600m)
1st 2022 Group 1 NZ Thoroughbred Breeders (1600m)
1st 2023 Group 1 Railway Stakes (1200m)
1st 2023 Group 1 BCD Group Sprint (1400m)
2nd 2023 Group 1 Canterbury Stakes (1300m)
1st 2023 Group 1 William Reid Stakes (1200m)
1st 2023 Group 1 Moir Stakes (1000m)
1st 2023 Group 1 Manikato Stakes (1200m)
1st 2024 Group 1 William Reid Stakes (1200m)
4th 2024 Group 1 T J Smith Stakes (1200m)