Naomi Osaka saved two match points and Serena Williams was taken to three sets as two of the favourites reached the Australian Open quarter-finals.
Having lost the opening set to Garbine Muguruza, Japan's Osaka was a break down in the second and faced two match points at 5-3 in the third.
But she won four games in a row to win 4-6 6-4 7-5 against the Spaniard, who is also a former world number one.
Williams then came through 6-4 2-6 6-4 against Belarusian Aryna Sabalenka.
The American surged into a 4-1 lead in an entertaining final set, before 22-year-old seventh seed Sabalenka broke back and levelled at 4-4.
But Williams held serve and then broke her opponent's serve to clinch the win and keep alive her hopes of a record-equalling 24th Grand Slam singles title.
"I am happy to get through that one because it wasn't easy," the 39-year-old 10th seed said. "I felt like I was there, even the games I lost were super close and just one shot here or there."
Williams will face second seed Simona Halep, who recovered to beat 19-year-old French Open champion Iga Swiatek 3-6 6-1 6-4.
It was the second successive match in which the Romanian has had to come from a set down, but she found form in the second set to edge past the Polish teenager in one hour and 50 minutes.
Halep said it was "tough" to think about playing Williams, whom she beat in the 2019 Wimbledon final.
"I will try to enjoy myself and I can only beat Serena if I play my best," she said.
Osaka, who won the second of her three Grand Slams at the Australian Open in 2019, will face Hsieh Su-Wei in the last eight.
The Taiwanese 35-year-old beat 19th seed Marketa Vondrousova 6-4 6-2 to become the oldest player to make a Grand Slam quarter-final debut in the Open era.
"I just knew it was going to be tough," said 23-year-old Osaka, who was facing 14th seed Muguruza for the first time.
"I feel like I was a bit intimidated because I knew that she was playing really well coming into this match. I feel like in the stressful points I just had to go within myself."
Latest Stories
-
On-field results have not reflected investment in Hearts of Oak – Vincent Sowah-Odotei
11 mins -
We should be able to evacuate all crude oil from broken-down vessel by close of day – NPA
12 mins -
Ghana’s external debt rework: Deal or no deal?
14 mins -
Government issues RFP for Saglemi Housing units
18 mins -
U.S. goverment invests in public servants working in Ghana’s public safety sector
37 mins -
Sam Jonah deems the absence of public purse accountability ‘pathetic’
41 mins -
Ghana is completely under-lawyered – Prof. Atuguba
47 mins -
Split vessel: NPA allays fears over discharging of crude oil content
58 mins -
Stonebwoy performs ‘Activate’ with Davido at his sold-out show at Madison Square Garden
1 hour -
Saint Kitts and Nevis reiterates constant position in favour of Morocco’s sovereignty over Sahara, territorial integrity
1 hour -
Ghanaian lawyers have strayed from Nkrumah’s vision for law in Ghana – Prof Atuguba
1 hour -
Accra set to hand over UNESCO World Book Capital title to Strasbourg
1 hour -
Rihanna: ‘I refused to buy maternity clothes’
1 hour -
Contempt case: Bench warrant issued for arrest of CID boss, Legal & Prosecutions D-G rescinded
2 hours -
I acknowledge your patience amid ‘dumsor’ – Akufo-Addo tells Ghanaians
2 hours