Naomi Osaka was forced to come from behind in her first match of the grass-court season as she beat Sachia Vickery in three sets at the Nottingham Open.
Osaka has enjoyed a breakthrough year, defeating Serena Williams, Simona Halep, Karolina Pliskova, Maria Sharapova and Victoria Azarenka among a host of others in 2018.
She beat Vickery en route to a shock triumph at Indian Wells, where Sharapova, Pliskova and Halep were all defeated by the 20-year-old. However, while that win was a routine 6-3 6-3 triumph, this was a much sterner test.
Osaka needed nearly two hours to secure victory, but her response to dropping the first set could hardly have been more emphatic as the third seed took command to prevail 3-6 6-1 6-2. Next up for Osaka is Denisa Allertova, a straight-sets winner over Kristie Ahn.
Second seed Magdalena Rybarikova also needed three sets against qualifier Elena-Gabriela Ruse, winning 6-0 3-6 6-1. Eighth seed Camila Giorgi did fall at the first hurdle in a 7-6 (7-4) 6-2 loss to Dalila Jakupovic.
There were also victories for Duan Ying-ying, Irina Falconi, Magdalena French and Vera Lapko.
The Rosmalen Grass Court Championships have been kind to top seed Coco Vandeweghe, and she continued her love affair by starting her quest for a third title in 's-Hertogenbosch with a 6-2 7-6 (7-1) success against Aliaksandra Sasnovich.
Vandeweghe, a winner in 2014 and 2016, now holds a 13-2 main-draw record at the tournament.
Sixth seed Alison Van Uytvanck made light work of home hope Richel Hogenkamp in a 6-1 6-2 triumph, but there were wins for the Dutch spectators to cheer courtesy of Bibiane Schoofs and Arantxa Rus.