Naomi Osaka is through to the third round of the Miami Open after beating former world number one Angelique Kerber in straight sets.

Osaka won the first three games of the match to jump out to an early lead, securing the set with a double-break before breaking early in the second to cruise to a 6-2 6-3 win.

The story of the match was Osaka's ease in winning points against Kerber's serve, winning 41 per cent (15/37) of Kerber's successful first serves, while the German could only win 11 per cent (3/27) in the same category.

Britain's top-ranked woman Emma Raducanu suffered another early exit, on the wrong end of Katerina Siniakova's comeback 3-6 6-4 7-5 win.