Caroline Wozniacki and Simona Halep secured safe passage to the third round of the Qatar Open.
The pair, who met in the Australian Open final when Wozniacki broke her grand slam duck, both enjoyed straight-sets wins in Doha.
But not every seed in action emerged unscathed, with the likes of Jelena Ostapenko, Kristina Mladenovic and Madison Keys dumped out.
Wozniacki and Halep, number one and two in the world respectively, were scarcely troubled in their matches.
The Dane saw off Carina Witthoeft 6-2 6-0, while Halep – whose own wait for a maiden grand slam goes on – was a 6-3 6-0 winner over Ekaterina Makarova.
It was the Romanian's first contest after January's Melbourne heartbreak and, having battled ankle and foot injuries, she was content with her fitness levels.
"I felt really well on court, I felt a little bit of pain but I just enjoyed the match too much," she said.
Halep next meets Anastasija Sevastova, who ousted Naomi Osaka, with Monica Niculescu – the beneficiary of Magdalena Rybarikova's retirement – awaiting Wozniacki.
A number of seeds sounded a signal of intent with impressive victories, not least of all reigning champion Karolina Pliskova and former world number one Angelique Kerber.
Pliskova, who beat Wozniacki in last year's final, overcame Alize Cornet 6-2 6-3, while Germany's Kerber eased past Samantha Stosur 6-4 6-1.
Meanwhile, third seed Elina Svitolina downed Marketa Vondrousova 6-2 6-4, and 16th seed Petra Kvitova – a winner in St Petersburg last month – ended Agnieszka Radwanska's challenge in three sets.
Julia Goerges and Johanna Konta were also among the seeds to make it through.
Not all the fancied players had things their own way, as evidenced by the early departures of Mladenovic, Keys and Ostapenko.
Teenager Anna Blinkova accounted for world number 13 Mladenovic in a surprise 6-3 6-3 success for the Russian.
US Open runner-up Keys was beaten 2-6 6-3 6-0 by American compatriot CiCi Bellis, while sixth seed Ostapenko suffered a shock loss to Mihaela Buzarnescu.
The French Open champion slumped to a 6-1 6-3 reverse against a player ranked 37 places below her.