The 2018 US Open champion Naomi Osaka survived a third-round scare before grinding out a 6-3, 6-7 (4), 6-2 victory over Ukrainian teenager Marta Kostyuk to reach the last 16 of the US Open. The Japanese fourth seed looked out of sorts in the second set tie-break but regrouped to secure the victory in the deciding set after two hours and 33 minutes against an 18-year-old who was making her debut at Flushing Meadows. Osaka once again wore heavy strapping on the left hamstring she injured last week while her mask bore the name of Ahmaud Arbery, a 25-year-old unarmed black man who was shot dead while out running in February. The world No 9 has masks with different names on for all seven rounds, and she showed just how much she wants to repeat her triumph of two years ago, wasting little time in the deciding set as she went up a double break before serving out the match at love. Osaka said of her opponent: “She was very good, like, I’m kind of scared of how she is going to be in the future”, adding: “I’m very tired right now. I don’t know, I just want to go into an ice bath. I’m not sure if this is classed as an emergency but I feel like I’m going to pass out … While I was playing, honestly, I was cursing myself out so you wouldn’t want to know what I was saying.” The two-times grand slam champion will face either the No 14 seed from Estonia, Anett Kontaveit, or the Polish No 24 seed Magda Linette in the fourth round. Another former champion, Angelique Kerber, is also through to the last 16 after a 6-3, 6-4 victory over Ann Li, and a fascinating contest awaits against in-form American Jennifer Brady, who knocked out Karolina Pliskova’s conqueror Caroline Garcia.