"She deserved this day after racing at the top level for an extended period of time.
Walter, the trainer of 13-time group one winner Tie The Knot, said Streama rated beside outstanding sprinter Spinning Hill among the mares he has prepared.
Walter also praised Blake Shinn who produced a superb ride to guide her to victory over the 2000m of Saturday's feature.
Shinn and Streama ($4.20 eq fav) stalked Leebaz ($7) before overhauling him in the straight to win by three-quarters of a length with the other market leader, Junoob, a further long neck third.
"Blake is the stable rider and is a great asset to me," Walter said.
Shinn said he went into the race with the plan to track the pace and it fell into place when Leebaz went forward.
James McDonald said Leebaz had come a long way in a short time.
"Look out for him in the spring, he will be a horse to be reckoned with," McDonald said.
Nash Rawiller, who rode Junoob, said he was pleased with the way the gelding adapted to Doomben.
"But I still think he will go better on a bigger track like Eagle Farm. Once I was able to get him into a rhythm he gave me a beautiful ride," he said.
Meanwhile, River Lad is poised to give trainer Natalie McCall her first runner in a Stradbroke Hcp after his gutsy win in the BRC Sprint.
River Lad ($9.50) outlasted Benny's Buttons ($5.50) to win the group three race by a long head, with Fire Up Fifi ($9.50) three lengths away third.
McCall, who trains a team of horses on the Sunshine Coast, has never previously had a runner in a group one race.
She has always had the $1 million Stradbroke (1400m) at Eagle Farm on June 7 as River Lad's winter carnival goal.
"He's nominated for the Doomben 10,000 next week but our plan all along has been to try and get him into the Stradbroke and we've achieved that by winning this race. I like to space his runs with three weeks between races so why change now?"
Tim Bell took River Lad straight to the lead and the gelding defied a spirited challenge from Benny's Buttons in the straight.
Fire Up Fifi resurrected her flagging winter carnival campaign with an improved effort to finish third after Queensland trainer Robert Heathcote put blinkers on the mare for the first time.
-AAP