The Helensburgh athlete was forced off the track in the first of three runs, leaving her with plenty of work to do to climb into the top four and progress to the second round of the competition.

That she did, the 21-year-old booking a place in the semi-finals alongside fellow Australian Lauren Reynolds.

Read more: Tokyo Olympics day six: more swimming gold for Australia

Sakakibara has fellowed a lengthy journey to get to Tokyo, with brother Kai seeing his Olympic dream dashed in a heavy crash last February.

Thursday marked his 25th birthday and he was in Japan at the family home to watch his little sister compete.

Talking to Channel 7 after the quarter-finals, Kai said the nerves were high as Saya fought to overcome a poor start.

"I was so scared," Kai said. "If she made one error, like she did in the first one, she would've been out, but she didn't and I feel great.

"Still tomorrow to go, so that's when I'll be really proud of her."

The first event could not have gone worse for Sakakibara, mid-race jostling seeing her pushed off the track before ultimately finishing in last place,

The second contest started in better fashion for the 21-year-old, Sakakibara hitting the front early and defending her lead.

That was until a crucial error just before the last turn, with the Australian dropping from first to fourth to leave her semi-final hopes hanging by a thread.

As a result, the pressure was on for the final run and Sakakibara delivered.

Again, she nailed the start and hit the front early, but this time she made no mistakes and took out the race to climb into fourth and secure a place in the semi-finals.

"She got a nice start, which she didn't in the first one," Kai said. "She had a bit of an average start and that's why she ended up so far behind.

"That (last) one she just nailed the start and kept it up all the way which was really good."