
Ridden by Kerrin McEvoy, she became awkwardly placed in a stop start affair, but hit the line hard when it mattered to win by a nose over her stablemate Another Dollar.
"It was a tough win because I made a decision to pop out and get on the back of Aloisia and then I was left stranded without cover," McEvoy said.
"It was a case of sit and suffer. They came at me from the 700m when I wanted to get going so I had to wait and suffer.
"She got bumped around the last part of the corner and it was a tough effort to pick herself up and get going again.
"She's gone to a new level when she's gone out in trip so the sky's the limit."
Youngstar is the third Queensland Oaks winner for Chris Waller in the past four years joining Winx and Egg Tart.
"It was a bit like a bicycle race the way they were changing positions. They were wheeling around and she's gone from a perfect spot one off the fence then shunted three and four wide," Waller said.
"They took off very early and she needed all of her qualities to come back on the line."

She has already won four of seven starts earning over $478,000 and is just at the start of what looks like a promising staying career with the Group I IBRC Queensland Derby in two weeks time still a possibility.
Bred to be an Oaks winner, Youngstar was bred by John and Karen Sheather and is a half-sister to stakes-placed Eleven Seconds and is the best of four winners from Irish bred Danehill mare Starspangled (IRE), a sister to Group III winner Downtown and daughter of Champion 3YO Filly User Friendly, a five-time Group I winner.
Bowness Stud sold the current yearling from Starspangled, a filly by Adelaide (IRE), for $80,000 at Inglis Easter to Anton Koolman Bloodstock.
Starspangled has a weanling colt by Dissident and was covered last spring by High Chaparral's champion son Dundeel.
Youngstar is the 22nd Group I winner for the much missed classic sire High Chaparral, who has been enjoying further success as a sire of sires through his star son So You Think, who sired Heavenly Though to win the Group III BRC Grand Prix earlier in the day at Doomben.