Victoria Azarenka began her bid for back-to-back titles for the second tournament in a row with a victory over herself, a treacherous Gulf wind as well as a middle ranking opponent at the Qatar Open on Wednesday.
The world number one, who defended her Australian Open title last time out, was within a point of losing the first three games before winning 6-2, 6-3 over Romina Oprandi, the world number 62 from Switzerland.
There were moments when the 23-year-old resorted to cursing and racket swishing, but Azarenka's irritation never got out of control and her grip on the match increased as her mind imposed its focus.
"It was a little bit of a slow start, and I had to adjust. I couldn't go for my shots, and I had to be a bit more patient," Azarenka, the defending champion in Qatar, said.
"She's tricky and plays so many different balls that you don't know what to expect. I had to focus more and move my feet more."
Azarenka was particularly pleased with the number of successful forays to the net she made, not usually an area of special strength for her.
"It's something I want to improve. I am solid from the baseline, so I tried to change it up a bit. I had a lot of opportunities to do that today."
Azarenka will next play Christina McHale, the world number 44 from the United States, who scored a good win over Lucie Safarova, a top 20 Czech by 6-4, 6-2.
A semi-final on Saturday with Agnieszka Radwanska, the world number four from Poland looks possible, but holding on to her world number one ranking will depend on Serena Williams not making the last four.
The Wimbledon, Olympic and US Open champion plays Thursday against Roberta Vinci, the 15th seeded Italian.
Williams' conqueror at the Australian Open will not however be troubling her again in this tournament.
Sloane Stephens led by a set and 5-3 and still could not get past Klara Zakopalova, the world number 24 from the Czech Republic, losing 4-6, 7-6 (7/5), 7-6 (7/5).
The American served for the match at 6-5 in the final set, and fought back from 1-5 down in the tie-break to 5-5, but this time missed her chance of tackling another big name.
Instead Zakopalova goes through to meet Maria Sharapova.
Radwanska reached the last 16 with comfortable 6-3, 6-2 win over Anastasia Rodionova, a qualifier from Australia, and next plays Ana Ivanovic, the former world number one from Serbia.