Elena Rybakina and Iga Swiatek power into Qatar Open semi-finals while Naomi Osaka falls
Top seed and defending champion Iga Swiatek also shook off a wobbly start in windy conditions before booking her place in the last four with a routine 6-4, 6-0 win over two-time Grand Slam champion Victoria Azarenka.
But it was the end of the road for Japan's four-time Grand Slam champion Naomi Osaka, who went down fighting 7-6(6), 7-6(5) against fellow former world number one Karolina Pliskova in a rematch of their Brisbane meeting last month.
Rybakina, who has lifted the Brisbane and Abu Dhabi trophies this year, dropped serve twice at the start of the clash but she stemmed the flow of errors from her racket and won five games in a row from 4-1 down to claim the opening set.
Fernandez showed more fight in the second set, but the 2021 US Open runner-up could not prevent former Wimbledon champion Rybakina from grabbing two more breaks and powering to victory on the back of some big hitting.
"It was a difficult match. I didn't start the set well. It took me some time to get used to Leylah's ball," Rybakina said after clinching a joint tour-leading 14th win of the season.
"She plays very different. Also a lefty. I'm really happy I managed to win the first one. After that, it was a bit easier to start the second."
Up next for the Moscow-born Kazakh is a clash with Anastasia Pavlyuchenkova after the unseeded Russian reached the Doha semi-finals for the first time following a 7-5, 6-4 win over American qualifier Danielle Collins.
"Hopefully it's going to be a great match to see. We know each other very well on the court and off the court. Hopefully I can recover and show some good tennis," Rybakina added.
Swiatek, the 2022 and 2023 winner, reeled off the last nine games against former world number one Azarenka to progress.
The 22-year-old Pole is looking to become the first player to win a WTA event three straight times since American Serena Williams claimed the Miami title from 2013-15.
"I'm really happy. Vika's a great champion. I feel she's been at the top in terms of the best players I watched when I was younger," Swiatek said of her 34-year-old opponent.
"I'm proud I can compete on the same court and play against Victoria and win. It's pretty crazy."
Swiatek will next face Pliskova, who wrapped up her ninth straight win with a gritty display against Osaka, who displayed more signs that she was rediscovering her best form following a maternity break.