Jockey Kathy O'Hara and sprinter Spaceboy proved a formidable team during the winter and the duo is preparing to take their partnership to the next level.

After showing ability as a juvenile with placings in the Golden Gift and Wyong Magic Millions, Spaceboy was struggling to fulfil his potential during his three-year-old season.

It wasn't until O'Hara jumped in the saddle at Kembla Grange in May that he broke his maiden and when she reunited with him a few runs later, the pair went on a three-start winning streak.

A victory at Wyong was followed by back-to-back successes in town and on Saturday at Rosehill, Spaceboy will step up to black-type grade in the Listed Starlight Stakes (1100m).

Trainer Gary Portelli has no doubt O'Hara has played a key role in giving the horse his new-found confidence.

"She really knows him and he has turned it around with Kath on," Portelli said.

"Hopefully she can continue that winning streak from Saturday onwards."

Spaceboy will contest the Starlight Stakes second up after a narrow defeat on Melbourne Cup day at Randwick when he started favourite.

Portelli said the horse had genuine excuses after missing his scheduled return in Brisbane 10 days earlier when the meeting was abandoned mid-program due to a thunderstorm.

Spaceboy was put back on the float to Sydney without racing and the unexpected delay proved costly.

"He missed a bit of work and I think that brought him undone over the last 100 metres (first up)," Portelli said.

"He has since had a barrier trial to keep him up to the mark but it's a big test for him.

"This is the strongest field he's met so far so we will see how he goes, but he has a light weight to offset it in 53 kilos."

Spaceboy will be one of two Starlight Stakes runners for the trainer, along with Single Bullet.

The latter has been plagued be feet problems but Portelli says the stable is finally on top of the issue after giving Single Bullet an extended break at the end of last spring.

He has been freshened since his unplaced run behind Athiri in September and if Saturday's race is run at a genuine tempo, Portelli expects the backmarker to be in the finish.

"I just wish he had drawn a bit softer because now we will have to ride him negative and see if he can come with the one big run but he can do that and there looks to be good speed in the race," Portelli said.

Godolphin's Varda has opened favourite for the Starlight Stakes and James Cummings is also expected to feature in the Festival Stakes (1500m) where he has three runners, headed by market leader Phaistos.