Doomben played host to its biggest crowd in more than four decades when 20,000 racegoers packed the racetrack for the Brisbane Race Club's annual Mekka Wednesday.

The Exhibition Wednesday meeting is usually held at Eagle Farm but was switched to Doomben this year.

The biggest post-war crowd at Doomben was in 1973 when 30,000 people were on hand to farewell legendary racehorse Gunsynd.

BRC chairman Neville Bell said just under 20,000 fans turned up when Black Caviar won the 2011 BTC Cup.

"However, Wednesday's crowd will be the equal if not more than the Black Caviar day. We had 12,000 pre sales and there have been about 7,000 to 8,000 walk ups."

"We won't have a final figure until Thursday but it looks as though it is the biggest crowd in 41 years."

There was plenty of action on the racetrack with apprentice Ruby Ride bouncing back from a serious fall on Sunday to win on Thinkhesaurus ($5) in the Mother Energy Handicap (1010m).

Ride was flung over the fence on her way to the barriers at Gatton on Sunday and taken to hospital.

"Thinkhesaurus is a smart horse and it was an incentive to get back in the saddle," Ride said.

South African jockey Robbie Fradd scored his first win at his first day riding in Brisbane when Vaz De Torres ($17) won the Corona Beach Handicap (1600m).

Fradd, who has ridden with great success in his homeland and Singapore, has moved to Queensland. He will be doing some of the riding for top trainer Rob Heathcote who has Vaz De Torres.

Trainer Stewart Mackinnon's confidence in the potential of his galloper Arawak ($13) paid off when the gelding won the Captain Morgan Handicap (1200m).

"One of Arawak's owners told me they had bought a horse and it was a `roarer'," Mackinnon said. "She asked me what that meant and I said it certainly didn't mean it was a lion.

"But Arawak had an operation and after getting over an infection he has shown plenty of potential."