DUBAI (AFP) -- Iga Swiatek survived a grueling affair against Sloane Stephens while Aryna Sabalenka blamed unfavorable conditions for her second round defeat to Donna Vekic in Dubai on Tuesday, Feb. 20.

The top-seeded Swiatek, who clinched her third consecutive Doha title on Saturday and had a first round bye in this event, had to dig deep to overcome former US Open champion Stephens, 6-4, 6-4, in a tug of war that witnessed eight breaks of serve and a combined 23 break points.

“We had a lot of tight games. I really needed to perform a little bit better in those important moments because I couldn't convert some break points. But I'm happy that at the end I did,” said Swiatek, who takes on two-time Dubai champion Elina Svitolina in the last-16.

“Yeah, it wasn't easy. It's nice that I played even a longer match here so I could adjust to the surface.”

Meanwhile, second seed Sabalenka fell 6-7 (5/7), 6-3, 6-0 to familiar foe Vekic in what was her first appearance since she successfully defended her title at the Australian Open last month.

Sabalenka blew a 7-6, 2-0 lead and lost the last nine games of the clash to succumb to her Croatian opponent in two hours and 22 minutes.

“I feel like the conditions here don't fit me well at all. It's really tricky for me to compete here in Dubai. Really tricky court for me. It's super-fast for me. Like no rhythm at all,” said the world number two.

“I'll stay here for a couple of days, then I'm going to move to L.A. and keep practising, keep fixing problems which happened today. Hopefully I'll be in better shape for Indian Wells.”

The 31st-ranked Vekic, who now owns a 6-2 head-to-head lead in lifetime meetings against Sabalenka, was aggressive throughout the match and enters her next clash with big-hitting Romanian Sorana Cirstea searching for her first WTA 1000 quarterfinal of her career.

"To be honest, I didn't have big expectations coming to Dubai. Told my coach that I'm taking this week as half holidays. I can tell you I spent more time on the beach than on the court. Maybe that's a good way going forward," laughed Vekic, who is now 9-13 against top-five opposition.

Azarenka retires 

Fourth seed Elena Rybakina advanced to the third round when her opponent Victoria Azarenka retired with an undisclosed injury. Azarenka took the first set before Rybakina levelled the match 4-6, 6-2.

The former world number one called the trainer between sets and decided to pull out of the contest to avoid further damage, sending Rybakina to a last-16 meeting with Polish qualifier Magdalena Frech.

Over on Court 1, Australian Open finalist Zheng Qinwen needed medical attention after dropping the opening set to Nao Hibino. The Chinese world number seven had her vitals checked and took some medication before coming back for a 5-7, 6-2, 6-2 victory.

“I’ve been sick for the past five days, I haven’t been feeling well, breathing hard,” said Zheng after the match.

“I just told myself keep going, everything can happen at a certain point. Never give up, even if I feel bad like today. I have to say thank you to myself to push hard for this match and win."

Earlier on Centre Court, eighth seed Maria Sakkari snapped a three-match losing streak and claimed her first-ever Dubai main-draw victory, on her fourth attempt, with a 6-2, 6-4 triumph over in-form American Emma Navarro.

After suffering opening round exits in Abu Dhabi and Doha, Sakkari was admittedly nervous ahead of her clash with Navarro, who is already a title-winner in 2024 and has amassed 13 victories in the first two months of the season.

"It was very tough. Last night I couldn't sleep just because I was overthinking about it and it wasn't easy. No one wants to keep losing first round. But I told myself to treat it as the first match of the season," said Sakkari, who faces Italian Jasmine Paolini next.

Sakkari is in search of a new coach having ended her six-year partnership with Tom Hill.

The Greek world number 11 briefly worked with Sergi Bruguera during the offseason and after the Australian Open but needs to find a full-time coach given Bruguera's commitment to ATP player Arthur Fils.

She is confident she will have found a new coach by the time Indian Wells commences next month.