A day after former Golden Slipper favourite Capitalist suffered his first defeat, his stablemate Defcon has staked his claim with victory in the Black Opal Stakes in Canberra.

But co-trainer Peter Snowden admitted his heart was in his mouth when the colt missed the start and had to skirt the field from last on the turn to win Sunday's 1200m-Group Three race with Blake Shinn aboard.

The TAB reacted by firming Defcon to $15 from $26 to win the $3.5 million Golden Slipper on March 19 but Snowden was non-committal, still getting over the drama of his win.

"We spoke spoke about four times how to ride him. That wasn't one of them," Snowden told Sky Thoroughbred Central.

"I was working out what I was going to say to him (Blake) but it's all pats on the back now.

"He had a bit on them. He has always had that great acceleration.

"A great turn of foot will take them a long way but we'll let the dust settle before we think about the Slipper."

Shinn said he was dismayed when the $1.90 favourite missed the start.

"When the barriers opened my heart sunk," he said.

"Before the race I thought I was on a good thing.

"I had to be patient and trust the horse's ability and hope they went fast enough in front and he was explosive.

"I had to trust the horse and I couldn't panic."

In the end, Defcon had a comfortable one-length margin over Flash Fibian ($31) with Prized Icon ($4.60) another 1-1/4 lengths third.

Capitalist has eased to $10 for the Slipper after his defeat in Saturday's Todman Stakes at Randwick with Blue Diamond Stakes winner Extreme Choice and runner-up Flying Artie heading the market at $2.80 and $6 respectively.

Both are trained in Melbourne by Mick Price.

Earlier on Canberra's feature race day, the Gai Waterhouse-trained Hippopus took out the Canberra Cup while Godolphin's Italy claimed the Canberra Guineas for jockey Christian Reith who rode Saturday's upset Randwick Guineas winner Le Romain.

Former New Zealander Cosmic Cube won his first Australian race when he took out the National Sprint for trainer David Van Dyke.