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 in the rankings if he reaches the Miami semi-finals, fired down 14 aces 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 the number one ranking after a surprise third-round loss at Indian Wells, will be American Jenson Brooksby, a 6-3 5-7 6-4 winner over Spain's Roberto Bautista Agut.
Spanish 14th seed Carlos Alcaraz will meet Stefanos Tsitsipas after both enjoyed straight-set wins over Marin Cilic and Alex de Minaur respectively.
The 18-year-old Alcaraz beat Tsitsipas in their only previous meeting, a five-set thriller at last year's US Open.
"He is a great player," the Greek third seed said of Alcaraz.
"For me it will be a great challenge, the ones that I like."
Indian Wells champion Taylor Fritz dispatched 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, recovering after falling behind 2-0 in the second set.
After the match the unseeded Osaka said she was in a different state of mind than last year when arriving at the Miami Open 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 the four-times Grand Slam champion and a first Miami semi-final will be 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 beat 16-year-old wildcard Linda Fruhvirtova 6-2 6-3 and will next meet Jessica Pegula, who reached the Miami quarter-finals for the first time after Anhelina Kalinina retired while trailing 6-0.
Badosa, who won the Sydney title this year and reached the semis at Indian Wells, told reporters it had been a tough day.
"I didn't wake up feeling well so I didn't know if I'd be able to finish the match," she said. "I always say I want to be a fighter no matter what so that's what I did. I kept fighting and I don't really know how I won."