Jameka will carry 52kg in her bid to win the $3.15million BMW Caulfield Cup, after being penalised half-a-kilo for her dominant Naturalism Stakes win on Saturday.
Racing Victoria chief handicapper Greg Carpenter decided on the penalty after the Ciaron Maher-trained mare put a space on her rivals in the 2000m contest at Caulfield.
The penalty was also applied to her Melbourne Cup weight, also coming to 52kg as it stands for the 3200m feature.
"Jameka was a decisive winner of the Naturalism Stakes, defeating last season's Sydney Cup winner,Gallante, by 3.75-lengths," Carpenter said.
"She carried 3kg less than Gallante on Saturday, and with the 0.5kg penalty she now has 1.5kg less than Gallante in both the Caulfield and Melbourne Cup.
"Historically speaking, Leilani (1974) and How Now (1976) are the only four-year-old mares to carry 52kg to victory in Caulfield Cup.
"As for the Melbourne Cup, Light Fingers (1965, 52.5kg) and Ethereal (2001, 52kg) are the only four-year-old mares to have won carrying 52kg or more."
Jameka is a $9 second-favourite with CrownBet for the Cup, behind Hartnell ($6).
Sacred Master, who won the Group 3 Newcastle Cup (2200m) on Friday, was also handed a 0.5kg penalty for his win, taking him to 51kg in the Caulfield Cup weights, meaning he is now equal 56th in the order of entry.
The Chris Waller-trained gelding wasn't penalised in the Melbourne Cup weights, remaining on 51kg.
Raw Impulse, who won the Listed Penang Trophy (1800m) by almost five lengths at Morphettville on Saturday, remains on 50kg for each of the Caulfield and Melbourne Cups.