De Sonic Boom lived up to her name inside the final furlong to win the Blue Diamond Preview (Fillies) in fine fashion – but it was very close to not happening.

It was the kind of thrilling second-last-to-first triumph that has her listed as a +800 chance with Bovada for the Group 2 Blue Diamond Prelude (Fillies) at Sandown this Saturday.

And after two average trials, father-and-son training team Anthony and Sam Freedman can thank part-owner James Bester for backing her to be competitive on debut.

Bester – also a leading bloodstock consultant to Coolmore – took Anthony aside after the talented two-year-old filly's first two trials.

She finished third from five at a jumpout over 750m at Balnarring on December 23, followed by a fourth from seven over 900 at Mornington on January 4.

That was when Bester told Freedman to just be patient with his young sprinter.

“They were umming and ahhing about putting her out, and I had a quiet word with Anthony,” the bloodstock professional said.

“I said to him ‘as long as she's feeling fine, give her another trial. At the very least we'll learn a bit more about her, and she'll learn a bit more before going out. And that will stand her in good stead coming back'.

“He's always very open to suggestions, and he said ‘I'll chat to Sam about it'.

“He and Sam had a chat and they said ‘OK, we'll trial her on the course proper finishing at the winning post at Sandown in a trial limited to Blue Diamond nominees. That'll tell us everything we need to know'.”

De Sonic Boom won that trial over 800m at Sandown on January 12, before going on to record her incredible three-quarter-length victory in the Blue Diamond Preview (Fillies) two weeks later.

“Well, she came out and won that trial after missing the start and being slow into stride,” Bester said.

“She sprinted in a very impressive fashion, and Mark Zahra said ‘wow, OK she could be the real deal'.

“As a result, we decided to press forward to that race.

“Why Mark Zahra got off her I'm not certain. But we were delighted to get Blake Shinn on, and I don't think we'll get him off now.”

Despite seeing her potential in her January 12 trial, there were still some slight doubts over whether De Sonic Boom could stand up on debut at Group 3 level.

Those question marks would have magnified when the filly was second-last at the turn coming onto the home straight.

But Shinn – one of Australia's best jockeys – never got flustered and allowed her to settle in before her incredible late burst of speed.

“We didn't know what to expect because we thought ‘well, a trial's one thing but a Blue Diamond Preview – you can't afford to miss the start and be slow into stride',” Bester said.

“That would've been the case at Caulfield, but this was at Sandown with a different uphill finish and longer straight.

“Because she was slow into stride, but Blake didn't panic.”

Bester was blown away by both the skill of Shinn and the raw talent of De Sonic Boom in the Blue Diamond Preview (Fillies).

“He allowed her to find her feet and roll along. Man, the acceleration she showed in the straight I thought was awesome,” the part-owner said.

“And her sectional times proved it. She ran fabulous sectionals.

“And wow, given that was her debut and she did things wrong – to win it like that was a very positive indicator for the Blue Diamond and Prelude.”

Bester said De Sonic Boom would handle the step up to 1100m for the Blue Diamond Prelude (Fillies) and 1200m for the Group 1 Blue Diamond Stakes – also at Sandown – on February 25.

“Just to give her a little more experience, the stable and Blake felt that she could deal with another 100 or 200m, or more,” he said.

“So I think with the added experience she can only get better.”

Bester is enjoying plenty of success at the moment, with Learning To Fly also producing a brilliant debut performance to win the Widden Stakes on January 28.

The Coolmore-owned filly is by American superstar Justify and out of Ennis Hill.

Ennis Hill is a retired mare by Fastnet Rock, while De Sonic Boom is out of Demasheen, who is also a Fastnet Rock mare.

“I'm particularly thrilled with her (De Sonic Boom). Like Ennis Hill, she's out of a Fastnet Rock mare, and they are worth their weight in gold,” Bester said.