Trainer Rob Heathcote chose a midweek maiden to unveil one of his main Brisbane winter carnival hopes at Doomben on Wednesday.

Heathcote was quick to declare his filly Sea Red could prove a Queensland Oaks filly next winter after her runaway win in the Sky Racing Three-Year-Old Fillies Maiden Plate (1350m).

Sea Red ($4.40) sat wide for the entire trip but came away for a 4-1/4 length win over Marlee's Luck ($7.50) with a long head to Wicked Daughter ($3.30) in third.

"She is my Oaks filly for next year," Heathcote said. "I know you might say she only just won a midweek maiden but she is very smart.

"I started her first-up here in a 1350-metre race because I plan to try her over longer trips this campaign with the Oaks in mind for the winter."

Sea Road completed a winning double for Heathcote as he had earlier won with Tale Of The Dragon.

Stewards took much longer than many in the crowd expected to uphold a protest involving galloper Buakaw.

When the field flashed across the line, Primed To Win ($5) beat Buakaw ($3.10) by a nose in the Peter Stein's 80th Handicap (1350m).

Aiden Holt, who rode Buakaw, quickly fired in a protest alleging interference on the home turn as well as over the final 100m.

After deliberating for five minutes, stewards found the later interference contributed to Buakaw's defeat.