World number one Naomi Osaka required three sets to seal her place in the second round of the Birmingham Classic on a rain-hit day in Edgbaston.
The top seed edged past Greece's Maria Sakkari 6-1 4-6 6-3 to set a duel with Kazakhstan's Yulia Putintseva, who defeated British wildcard Harriet Dart.
"I feel, like, every day that I play on grass of course I'm going to learn how to play better, but for now I'm just really happy I was able to win that match," said Osaka.
"I think it's really important for me. I'm only playing this tournament before Wimbledon, so I would love to get a lot of matches in and sort of build my confidence up."
Osaka's rival for the number one ranking, Ashleigh Barty, was among a group of players including Venus Williams who saw their matches postponed until Wednesday.
There were wins for eighth seed Julia Goerges and 2017 French Open winner Jelena Ostapenko, who now meets British number one Johanna Konta.
One other intriguing contest looks set to be that of the Pliskova twin sisters, Karolina and Kristyna, in what will be their ninth head-to-head.