Serena Williams produced a stunning performance to beat second seed Simona Halep and set up an Australian Open semi-final with Naomi Osaka.
"I think this is the best match I've played this tournament," said Williams, who moved well and hit 24 winners.
Earlier on Tuesday, Osaka cruised past Hsieh Su-wei in just 66 minutes to reach the last four.
The Japanese third seed, who won the second of her three Grand Slam titles at Melbourne Park in 2019, beat the Taiwanese 6-2 6-2.
Now Osaka will face 10th seed Williams - a seven-time champion in Melbourne - on Thursday for a place in Saturday's final.