Punters have plunged Pop Culture into equal favouritism in her bid to become the first mare to win the WA Oaks and GRD Perth Cup double.
TAB fixed-odds manager Ben Pomatti said Pop Culture had been backed from $6.50 into $5.50 favouritism with Black Tycoon and Rohan since the barrier draw last Friday.
The TAB is expecting to pay out a six-figure sum if the five-year-old wins tomorrow's $500,000 Group 2 cup (2400m) at Ascot.
"She was well backed from a starting price at $21 in all-in betting and we have written her strongly in the final field," Pomatti said.
"She is our worst liability."
Trainer Colin Webster prepared Rogan Josh to run second to King Of Saxony in the 1999 Perth Cup, when it was run over 3200m.
Webster recommended "Cups King" Bart Cummings prepare Rogan Josh for the 1999 Melbourne Cup (3200m), in which he was ridden by WA-born jockey John Marshall and beat the Godolphin-owned $51 outsider Central Park.
Webster's outstanding stayer Beau Heed, who won successive Pinjarra and Bunbury cups doubles in 1995 and '96, ran third to Time Frame in the 1997 cup and Wolf City finished third to Philomel in the 1976 cup.
Pop Culture was stepped up to 2200m for only the second time this campaign when she knuckled down to beat cup rival Knightlike in the ATA Handicap two weeks ago, giving Webster, the Australian Trainers' Association WA president his first win in the race.
Pop Culture jumped from the widest gate (16) when she ran an eye-catching fourth to Talent Show in the Perth Cup last January.
Troy Turner, who rode Rogan Josh and Beau Heed at their cup placings, will be aboard the daughter of WA's No.1 sire Blackfriars. She has drawn perfectly in gate four and is on the minimum weight on 54kg.
"I liked the way she dug deep to fight off Knightlike," Webster said.
"I like horses who show grit when they are asked. She has pulled up an absolute treat."
The 2007 WA Oaks winner Westerly Breeze ran third to Cats Fun in the 2008 cup and Palatious won the 1993 Perth Cup after finishing runner-up to Jevresa in the 1992 WA Oaks.
"The biggest improvement for her will be stepping up the extra 200m," Webster said.
"She is better suited at 2400m than 2200m.
"That was a good, hard and solid lead-up run for her into the cup. She will be fitter because of that.
"She has a beautiful barrier. She is more dour now than ever."
Keepers Court, firm at $17, is the best-backed runner of trainer Adam Durrant's pair. New acquisition Marden was at $13.
There has been support for Starlight Lady, with the seven-year-old backed from $41 into $26.