Australia have achieved their best ever qualifying results at a world gymnastics championships after the women's team secured places in three apparatus and the all-around final in London on Wednesday.

Lauren Mitchell stamped herself as a potential medallist by qualifying third for the all-around final with a score of 56.675, behind only American Rebecca Bross (57.400) and Ana Porgras of Romania (57.300).

The 18-year-old from Perth also qualified fifth in the beam and floor disciplines, but not without some drama.

Coach Peggy Liddick protested Mitchell's beam score, successfully having it raised from 14.2 to 14.4, which elevated the Beijing Olympian to the apparatus's final.

"(It's the) best result I've had at a world championships," Mitchell said.

"I've worked hard since the Olympics, on my vault and bars, to become a true all-rounder and it's paid off for me tonight.

"I hope I can repeat this in the finals."

Seventeen-year-old Larrissa Miller, the baby of the team, made an impressive world championships debut on the uneven bars with a score of 14.65, qualifying for the final in fifth.

"I was really pleased with my performance," Brisbane's Miller said.

"It was an awesome experience and once I got through my warm-up routine I just relaxed and all my training paid off.

"I'm rapt that I've made the final in my first world championships."

The breakthrough day for the Australian women comes after Prashanth Sellathurai qualified in fifth place on Tuesday for the final of the men's pommel horse.

But women's coach Liddick warned it would mean little if the team did not back up their strong performances in the finals.

"Both athletes have trained extremely hard and their work paid off tonight," she said. "It's now up to the girls to convert these opportunities."

On a sour note for Australia, Shona Morgan's second world championships ended in disappointment when she dislocated her knee during a warm-up on the vault on Wednesday morning.

The 19-year-old from Melbourne was rushed to a London hospital for treatment.

"She's OK but she has a serious knee injury," Gymnastics Australia chief executive Jane Allen said.

"She should be OK once she has some proper treatment."

AAP