Emma Raducanu says she has found her "competitive spirit" after defeating 17th seed Amanda Anismova in Miami to reach her first WTA 1,000 quarter-final.

The Briton was in brilliant form from the off against her American opponent and needed just 24 minutes to secure the first set on her way to a blistering 6-1 6-3 win.

It is the first time since her US Open triumph in 2021 that Raducanu has won four WTA main-draw matches in a row, and she was dominant in sweeping Anisimova aside.

"The biggest thing I'm proud of is just finding the competitive spirit and being there for every ball and drawing that out of myself," Raducanu said.

"I think that's kind of been missing in the last few months and even a few years at times."

Prior to this tournament, Raducanu had lost five of six matches since the Australian Open - and last week ended her partnership with coach Vladimir Platenik after just two weeks.

"I've come a long way in the last week since Indian Wells, I wasn't necessarily feeling great about my tennis, about everything," the 22-year-old told Sky Sports.

"This week I have some really good people around me who I trust and who I have fun with off the court as well. That's extremely important.

"When I play my best I am definitely authentic, true to myself and creative. I feel when I am boxed into a regimented way then I am not able to express myself in the same way. So I'm happy with how I realised that this week."

Raducanu broke in the opening game of the match and raced through the opening set without losing a point on her own serve.

It was her returning that most impressed, though, as she continually put pressure on the Anisimova serve.

The American grew increasingly angry as the first set went on and appeared to be struggling with a right wrist issue.

Following a medical timeout between sets, she was much improved but could still not prevent Raducanu breaking to go 3-1 up in the second.

Anisimova broke straight back but Raducanu once again demonstrated the resilience she has shown in Miami, breaking again before confidently serving out for the match.

"I'm walking on to the court knowing that I'm going to be there for every point, every ball," the British number two said.

"So far that's really worked. Also, I think on the match court now I'm just thinking less, which is probably a good thing, and trying to just let my creativity come out because I think that's when I'm playing my best tennis."

Raducanu will play world number four Jessica Pegula in the last eight after the American beat Ukraine's Marta Kostyuk 6-2 6-3.

Elsewhere, world number one Aryna Sabalenka is also through to the quarter-finals after a 6-4 6-4 win over defending champion Danielle Collins of the USA.

The Belarusian secured the only break of the first set at 3-3 and, after breaking in the opening game of the second, went on to complete the victory in an hour and 19 minutes.

Italy's Jasmine Paolini came from a set down to overcome four-time Grand Slam champion Naomi Osaka 3-6 6-4 6-4.

World number two Iga Swiatek pressed on with her quest for a first title of 2025, beating Ukraine's Elina Svitolina 7-6 (7-5) 6-3 to set up a meeting with 19-year-old wildcard Alexandra Eala, from the Philippines, who will be playing in her first WTA quarter-final.

Eala's eye-catching run in Miami continued after her fourth-round opponent, 10th seed Paula Badosa, withdrew before the match because of a lower back injury.

There was disappointment for world number three Coco Gauff who was beaten 6-4 6-4 by Poland's Magda Linette.

In the men's singles, Alexander Zverev overcame a slow start to beat Australia's Jordan Thompson 7-5 6-4.

The German was 4-1 down in the first set before fighting back to win eight of the next nine games and set up a fourth-round tie against France's Arthur Fils, who beat Frances Tiafoe 7-6 (13-11) 5-7 6-2.

Taylor Fritz also advanced with a 7-5 6-3 win against Canada's Denis Shapovalov, but his American compatriot Tommy Paul suffered a 6-2 7-6 (7-4) defeat by Argentina's Francisco Cerundolo.

Australian 10th seed Alex de Minaur fought back to beat Brazilian 18-year-old Joao Fonseca 5-7 7-5 6-3 and set up a last-16 meeting with Italy's Matteo Berrettini.