While Kathy O'Hara was at home nursing a sore head, Brenton Avdulla stepped into the breach to ride one of her favourite horses to win the Starlight Stakes at Rosehill.

O'Hara suffered a concussion and a nasty gash when she fell at Randwick on Friday and was kicked by a following horse.

Avdulla got on the free-running Zaratone ($7) in the Listed 1100m sprint and the veteran gelding made the race a one-act affair, beating the $1.80 favourite Heart Testa by 1-3/4 lengths.

Trainer Bjorn Baker said eight-year-old Zaratone, who came to him earlier this year after racing for Nick Olive in Canberra, was a stable favourite.

"He is a lovely horse and such a pleasure to have around the stable," Baker said.

"My feelings are with Kathy. She's ridden him perfectly all the time.

"Her health is paramount and she'll be back on him when she's right."

Avdulla said he really didn't have too much to do.

"I was able to get a soft lead and he took off on the corner," he said.

"I can't take much credit."

Baker said he would look for another suitable sprint for Zaratone in the coming weeks.

"I think he's the best I've had him since he came to me," he said.

"I was the lucky recipient of a horse who was ready to go. He's a sound horse and only knows one way to run and that's in front."

O'Hara, who spent the night in hospital, told her Twitter followers she had a blinding headache and posted a gory picture of her wound but she still managed to find the strength to watch one of her favourite horses win.

"go boy! So proud of him, well done!," she tweeted.