MIAMI, March 29 — 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 per cent of his first-serve points and broke Martinez three times to secure victory in 84 minutes.

"I just felt like I had to be more consistent, and the more consistent one today would win,” Medvedev said.

"I managed to just make a few less errors at important moments, serve even better, and it was a small margin but I managed to win and I’m really happy.”

Up next for the Russian, who lost his world number one ranking after a surprise third-round loss at Indian Wells two weeks ago, will be American Jenson Brooksby, a 6-3 5-7 6-4 winner over Spanish 15th seed Roberto Bautista Agut.

Spanish 14th seed Carlos Alcaraz will meet Greek third seed Stefanos Tsitsipas in a mouth-watering fourth-round clash after both enjoyed straight-set wins over Marin Cilic andAlex de Minaur respectively.

The 18-year-old Alcaraz beat Tsitsipas in their only previous meeting, a five-set thriller in the third round of last year’s US Open.

"He is a great player,” Tsitsipas said of Alcaraz.

"For me it will be a great challenge, the ones that I like.”

Indian Wells champion Taylor Fritz converted both of his break point opportunities to dispatch fellow American Tommy Paul 7-6(2) 6-4 and will meet Serbian Miomir Kecmanovic, a 7-6(4) 6-3 winner over Sebastian Korda.

Fritz said it is all about managing expectations.

"I didn’t really think about winning Indian Wells until I had match point in the final,” he said.

"So I’m approaching this one the same way. I don’t expect to win the tournament, but I take it one match at a time, and you never know.”

Osaka serves up win

Japan’s Osaka reached the quarter-finals for a second consecutive year with a 6-3 6-4 win over American Alison Riske during which she won 70 per cent of her first-serve points and recovered after falling behind 2-0 in the second set.

After the match the unseeded Osaka expressed how she is in a different state of mind than last year when arriving at the Miami Open ranked second after winning the Australian Open.

"It’s really funny for me because last year I made it to the (Miami) quarters too but it was after I won Australia and I wasn’t that grateful, I kind of expected to win,” said Osaka.

"But I’m in the same position this year and I am so like, this is really like one of the funnest times of my life.”

Standing between four-times Grand Slam champion Osaka and a first Miami semi-final spot will be ninth-seeded Australian Open finalist Danielle Collins, who beat Tunisian eighth seed Ons Jabeur 6-2 6-4.

Poland’s new world number one Iga Swiatek eased past 14th seed Coco Gauff 6-3 6-1 and will next face Petra Kvitova after the Czech defeated Veronika Kudermatova 7-6(5) 6-4 to reach the quarters.

Spanish fifth seed Paula Badosa closes out the evening session against Czech wildcard Linda Fruhvirtova. — Reuters