The Lion has claimed a second Highway Handicap win to ease the pain of what should have been his third.

A post-race drug test after his victory at Randwick in June was found to contain an illegal substance and the gelding was stripped of his win.

Trainer Michelle Fleming admitted at an inquiry she had given The Lion a relaxant to keep him calm during a clipping.

Racing NSW stewards found Fleming had failed to seek veterinary advice and administered a greater than recommended dose, however the amount of the drug detected was low.

She was fined $8000 and The Lion was disqualified.

The Lion won his first Highway race for country-trained horses at Rosehill in June and Saturday's Randwick win over 1100m took his record to four wins from 19 starts.

Fleming said Saturday's large field had made her nervous.

"He's a good horse," she said. "He does everything I ask him to."

She laughed off suggestions she had snuck a look at favourite Burning Crown before the race

"Well, I actually bought him down with me," she said.

Runner-up Can't Find Snippy ($17) led the field for most of the race before Rachel King brought The Lion ($14) with a late run to win going away by 1-1/2 lengths.

Burning Crown ($2.15) was another long neck third at his first attempt on rain-affected ground.

King, who brought up a double with the pick-up ride on the winner when Chris O'Brien was unavailable, said The Lion had more wins in store.

"There's a few more in him," King said.

"He was pretty straightforward. I just sat there and let him do his thing.

"We surged around a bit, but from about the 500 he actually towed me into it."