Naomi Osaka has finally cracked the grass-court code. The former world number one sprinted into Wimbledon's fourth round for the first time in her career on Friday, demolishing Russia's Daria Kasatkina 6-1, 6-3 in just 65 minutes on Court One. The Japanese 14th seed had entered the tournament wearing yet another showstopping outfit, but it was her play that turned heads as she dominated from start to finish. All four of Osaka's Grand Slam singles titles have come on hard courts, and the 28-year-old has long struggled to translate her powerful, big-hitting game to the slower surfaces of Roland Garros and the faster grass of southwest London. But something seems to have clicked. The victory over Kasatkina was her third straight win at Wimbledon without dropping a set, and she has now won nine consecutive sets on grass this summer. "I definitely felt really good today. I've played a lot of matches on grass for the past two weeks, so I felt really confident," Osaka said after the match. The breakthrough comes less than five weeks after Osaka reached the last 16 at the French Open for the first time — another surface that had historically frustrated her. She built that momentum by making her first grass-court final at the Bad Homburg Open in Germany last month, though she was forced to retire injured at the start of the second set against Karolina Muchova. That run, despite the painful ending, appears to have given her exactly what she needed: belief on grass. Next up for Osaka could be a blockbuster showdown with top seed Aryna Sabalenka of Belarus, if Sabalenka defeats Latvia's Jelena Ostapenko later on Friday. It would be a rematch of their quarterfinal at the Australian Open in January, which Osaka lost. But on current form, Osaka looks capable of making history on a surface that has, until now, left her chasing.