Williamson will team up with his regular drive Luisanabelle Midfrew in the second of two Breeders Crown semifinals on Saturday - the first time he has driven in Victoria, after driving in a junior drivers series in New South Wales in 2013.
Luisanabelle Midfrew will stay in Australia with new trainer John McCarthy after the Breeders Crown finals next week but her New Zealand trainer, Nigel McGrath, and owners John and Rebecca Mooney are keen to retain Williamson's services for the series.
And at least one piece of the puzzle has fallen into place after the daughter of American Ideal drew barrier 2 in a 10-horse semifinal, faring better than likely rival Rocknroll Magic.
It is a change in fortunes for Luisanabelle Midfrew, whose task of beating the All Stars Stables trio of Golden Goddess, Piccadilly Princess and Dream About Me was made even harder by bad draws in the features.
''She was getting good draws at the start of the season - you can't get them every week - but in the last couple of big races, the Oaks and the Jewels, she was getting bad draws.''
Williamson's first task when studying the form of Saturday's rivals is to figure out what Gina Grace, the only horse drawn inside him, is capable of.
''I'll have to have a look at what [Gina Grace] does, but hopefully [Luisanabelle Midfrew] has enough gate speed to get out and get across. That would be great.''
If Luisanabelle Midfrew races even close to her New Zealand form, where she was good enough to beat the older mares in the group 1 New Zealand Breeders Stakes, finishing in the top six and qualifying for the final should be well within her reach.
Williamson said he was slightly disappointed by the pacer's effort at Addington 12 days ago when she was beaten by Aquickone.
''Hopefully, she was just in need of the run and will bounce off the canvas from that.
''She just didn't feel like she normally does, so hopefully there is a lot of improvement in her. She looked a wee bit big.''
In contrast to Luisanabelle Midfrew, Our Waikiki Beach has been handed a tricky start to his Breeders Crown defence.
The exceptional 3yr-old confirmed his place as favourite for the series with a dominant win at Melton last Saturday but his path to the final has been made more difficult by a bad draw in his semifinal.
The winner of 21 of his 22 starts will start from the inside of the second line in his 2150m semifinal.
The other New Zealand-trained 3yr-old in the series, Franco Cristiano, has an easier path. He has drawn barrier 3 in the other semi and will be expected to win for John Dunn.
Purdon did not have a lot of luck with barrier draws for his other series favourites, with both Pacing Major (2yr-old boys) and Partyon (juvenile fillies) drawing the second line, although My MacKenzie drew barrier 1 in the other 3yr-old fillies semi.
- Additional reporting The New Zealand Herald
