The Japanese US Open champion, 21, had too much firepower for Svitolina, triumphing 6-4 6-1 in Melbourne.

Sixth seed Svitolina, who is still to go beyond the quarter-finals at a Grand Slam, received treatment for a neck and shoulder injury during the second set.

Osaka will face Karolina Pliskova in the last four on Thursday after the Czech player overcame Serena Williams.

The seventh seed fought from 5-1 down in the decider and saved four match points to record a 6-4 4-6 7-5 win.

Fourth seed Osaka says that winning the US Open in September has given her the taste of success in the biggest events.

"I know that a few months ago I would have given anything to be in the semi-finals of a Slam," she said.

"But it's this weird feeling of, like, you want to do the next big thing. Especially now that I won a Grand Slam, I feel like I want to win another on.

"I'm so close and I just want to keep going."

'I tried to not get angry'

Osaka announced herself on the world stage with her hugely impressive victory over Williams at Flushing Meadows, although her achievement was overshadowed by the American's outburst at umpire Carlos Ramos.

She has the chance to become world number one after this tournament and looked a class apart against Svitolina, who was affected by a neck and shoulder issue which needed treatment during her third-round match.

There was no sign of an problem in the first five games as both players held serve, but the final five games of the first set were all breaks with Osaka striking the decisive blow when Svitolina netted a backhand.

The second set was much more straightforward, once a lucky net cord gave Osaka the first break in the second game.

Svitolina received treatment at the changeover when 3-0 down but to no noticeable effect and Osaka feasted on her weak second serve, winning 16 of 22 points on it.

The Ukrainian managed to halt a run of six games in a row for Osaka but a smashed winner sealed victory in one hour and 12 minutes.

"I tried to be consistent or as consistent as I can be. She's really good but unfortunately she was injured. But playing against her injured was really tough," said Osaka.

"For me, today, I had one goal - it was to try as hard as I can and not get angry.

"I didn't do that well in the past two rounds, but I played well today."

Svitolina 'couldn't handle' injury

Elina Svitolina said afterwards she had been in pain from the beginning of the Australian Open

Svitolina, who won the season-ending WTA Finals in Singapore in October, was always on the back foot against Osaka, with the Japanese's total of 31 winners 20 more than her opponent managed.

Asked if her injury was a shoulder or neck problem, Svitolina said "a bit of both".

She intends to have a scan when she returns to Europe and might have a break from the WTA Tour so the issue can be resolved.

"I couldn't produce 100% the game I wanted but in the end she played better," said Svitolina.

"I felt pain from the beginning of the tournament here. It was going and coming back, today it was a little bit worse than I expected.

"It is normal to have tension during a Grand Slam but unfortunately I couldn't handle it today."