Top seed Daniil Medvedev moved a step closer to reclaiming the world number one ranking as he beat Spaniard Pedro Martinez 6-3 6-4 on Monday to reach the last 16 at the Miami Open while Naomi Osaka cruised into the quarter-finals of the women's draw.
Medvedev, who can replace Novak Djokovic on top of the world rankings if he reaches the Miami semi-finals, fired down 14 aces, won 79% of his first-serve points and broke Martinez three times to secure victory in 84 minutes.