Sabalenka battles 'tough moments' to reach Australian Open semis
The 24-year-old Sabalenka is the highest-ranked player left in the draw and plays unseeded Magda Linette of Poland for a place in Saturday's final.
The Belarusian fifth seed was constantly under pressure in a 1hr 49min tussle on Rod Laver Arena before grittily coming through 6-3, 6-2 against unseeded Croat Vekic.
"There were a lot of really tough moments," said Sabalenka, who faced break points in all of her service games and is closing on a first Grand Slam crown.
"I just kept saying: 'Just stay in the game, fight for it, don't give her easy points, make her work for it.'"
Thursday's other semi-final pits her 33-year-old compatriot Victoria Azarenka against Elena Rybakina, leaving the possibility of a first all-Belarusian final in Grand Slam history.
"I really want it to happen. I know that Vika will do everything she can to make it happen," Sabalenka said of two-time Australian Open champion Azarenka.
"I will do everything I can to make it happen. That's going to be history. That's going to be just unbelievable and tough to realise that this actually happens."
Sabalenka came into the match as many observers' favourite for the Melbourne crown. She won the recent WTA Adelaide International and had not dropped a set in 2023 in eight matches.
The world number five had reached the US Open semi-finals in each of the last two seasons and made the final four at Wimbledon in 2021.
By contrast, 64th-ranked Vekic, aged 26, has been working her way back to the top 20 after knee surgery two years ago that she thought might end her career.
But Vekic had won five of the pair's six meetings, including at the Tokyo Olympics and in San Diego last October, and was able to put fierce pressure on Sabalenka's serve early on.
'Work for it'
The Belarusian broke Vekic to love for 3-1 but the Croat got straight back on terms. Her serve remained shaky though, not helped by seven double faults in the first three games.
Vekic tried to mix up her play, delicate drop shots and punishing forehand winners creating more openings.
But this version of Sabalenka, who has so often been unhinged by nerves in the past, refused to buckle and took a decisive break to lead 5-3. She secured an attritional first set after exactly an hour.
Sabalenka explained how she is able now to get through the tricky moments.
"Before I would go for aces, go for crazy shots to get out from that situation easily," she said.
"Now I keep saying: 'No, work for it. It's not going to be easy. You have your shots, you have your serve. Just work for it,'" she said.
"It's just a different approach."
Sabalenka put Vekic under more pressure at the start of the second set, stretching out to a double break for 3-0 as the Croat's double fault count soared to 12.
Sabalenka wobbled when serving for the match at 5-2, serving two double faults and facing break points.
After three deuces and with the tension rising, Sabalenka got over the line on her first match point.
"I don't think I can be disappointed or think too much about the break points because she played them really well," said Vekic, who fashioned 14 points to break Sabalenka's serve, but could only convert two.
"The only thing I can really be disappointed about and try to work on is my serve really let me down today. I was struggling a lot.
"It was one day, a bad day in the office, I hope."