Naomi Osaka, Alexander Zverev survive French Open scare

Japan's Naomi Osaka battled back from a set down to reach the second round of the French Open.

The top seed overcame Slovakia's Anna Karolina Schmiedlova 0-6, 7-6, 6-1.

She will next face Victoria Azarenka, who registered a 6-4, 7-6 win over 2017 champion Jelena Ostapenko.

Elsewhere, defending champion Simona Halep struggled in a 6-2, 3-6, 6-1 win over world number 47 Ajla Tomljanovic.

In the men’s competition, fifth seed Alexander Zverev needed four hours to beat Australia’s John Millman 7-6, 6-3, 2-6, 6-7, 6-3

Meanwhile, 40-year-old Ivo Karlovic became the oldest man to win a grand slam match since 1978.

The Croatian defeated Spain’s Feliciano Lopez 7-6, 7-5, 6-7, 7-5.