Two-time Grand Slam champion Naomi Osaka began her 2020 season with a 6-2 6-7(4) 6-3 victory over Maria Sakkari in the opening round of the Brisbane International.
Former U.S. Open champion Sloane Stephens, 24th in the WTA rankings, fell at the first hurdle to Liudmila Samsonova, who is ranked more than 100 places below her.
The 129th ranked Russian won 6-4 2-6 6-3.
Samsonova next faces former Wimbledon champion Petra Kvitova who overcame a slow start and reeled off 12 of the last 13 games to down another Russian in Anastasia Pavlyuchenkova 2-6 6-1 6-0.
Wildcard Maria Sharapova, playing her first match since losing in the first round of last year’s U.S. Open, was beaten 3-6 6-1 7-6(3) by Jennifer Brady.
The American qualifier will take on world number one Ash Barty in the second round.
Eighth seed Madison Keys advanced with a 6-3 6-2 win over the Czech Republic’s Marie Bouzkova.