Danny O'Brien is not known for his success with two-year-olds but well-bred Star Witness could break with tradition for the stable after an exciting Moonee Valley debut.

Among the first progeny of Starcraft to race, the colt looked as if his waywardness would beat him in the straight before Nick Hall lifted him on the line to beat another first starter, Flokkati, by a short half-head in Saturday's Tatts Group Plate (1000m).

Third-placed Josimar was a half-neck away third and, to the relief of O'Brien, his jockey Dan Nikolic unsuccessfully protested against Star Witness who shifted out near the winning post.

O'Brien has had a strong link with Star Witness' family having trained his dam Leone Chiara to seven city wins including an Adelaide Stakes victory.

He also trained Leone Chiara's Ascot Vale Stakes-winning brother Ferocity and had a brief association with her four-time Group race-winning sister Chinchilla Rose.

"He (Star Witness) is Leone Chiara's first foal and it is one of the better families in Australia in the last 10 years so hopefully he can do the family credit," O'Brien said.

Star Witness was a $150,000 Magic Millions yearling and in early training was a standout among 60 youngsters O'Brien has on his books.

"Half are New Zealand-bred so I don't have a lot in the system that would race before they are late two or three, but he was such a natural," O'Brien said.

"We only gave him one trial but he is one of those horses who is very mature mentally and physically and has been thriving so we decided to race him instead of giving him another one (trial)."

O'Brien said there was good reason to think that Star Witness would train on, not the least being that he is the spitting image of his mother.

His sire Starcraft was a multiple Group One winner with successes at the elite level in Australia, New Zealand and Europe.

"I think there might be a lot more scope there," O'Brien said.

He said Star Witness would return to Moonee Valley for his next start in the Listed St Albans Plate (1000m) on December 14 but was highly unlikely to contest the Gold Coast Magic Millions (1200m) in January.