Britain's Emma Raducanu says she needs to be "aggressive" if she is to compete against the world's best players after losing to Amanda Anisimova in only 52 minutes at Indian Wells.

American sixth seed Anisimova, a runner-up at Wimbledon and the US Open last year, raced to a 6-1 6-1 victory to reach the fourth round in California.

Raducanu lost her serve in the opening game, won only 11 points in the first set and was 3-0 down in the second before managing to hold serve.

"When I'm playing someone who's at the top like that, I think they have an extra 10 miles an hour on their serve than me," Raducanu said.

"If I'm not feeling it, that gap feels more evident in terms of weight of shot, in terms of power.

"You just feel a little bit behind and your punches aren't landing as much as theirs are.

"I need to obviously be aggressive when playing those players, but I think there's still a long way to go to be doing that and I need to use my strengths and probably mix it up a bit more."

Having enlisted Mark Petchey as a temporary coach after parting with Francisco Roig in January, Raducanu said last week that she is hoping to rediscover her "natural way of playing" in an attempt to build towards the form that won her the 2021 US Open.

Raducanu, who beat Anastasia Zakharova 6-1 6-3 in the second round, said: "It's difficult to read much into the game, other than the starting the point really, as there were no rallies.

"But I have to look at what I achieved in the last nine days of practice since I arrived here, and the first match was a good one for me.

"Today I could let it get me down if I wanted to, but overall I think the days have been better than not."

Anisimova will face 19-year-old Canadian Victoria Mboko, the 10th seed, in the last 16.

This was another sobering outing for Raducanu against one of the world's very best.

Anismiova was outstanding from the first ball and consistently took control of the point from the first serve or the first return.

There was very little resistance from Raducanu, who never got out of the blocks and did not serve well.

She has made it clear she wants to take the ball on, and try and be aggressive against the best players in the world.

But as she later admitted, she is still a long way from doing that well enough to be competitive at the highest level.

Raducanu takes inspiration from the achievements of Simona Halep and Jessica Pegula.

Both are a similar height and, as she said afterwards, they "find a way to really dig in".

World number four Coco Gauff retired from her third-round match against Alexandra Eala with a "scary" arm injury that "felt like it was on fire".

It is only the second time in her career that Gauff, a two-time Grand Slam singles champion, has retired during a match.

The American said she would "rather finish the match and lose 6-0" but retired when trailing 6-2 2-0.

"It felt like a firework was going off inside of my arm, and then my whole arm felt like it was on fire," Gauff said.

"As the match played, it got progressively worse, even on shots that I wasn't even using my left arm for."

Gauff took a medical timeout for treatment at 5-2 and the trainer returned at the end of the set to wrap her forearm.

The 21-year-old decided "it was better to stop" after 54 minutes on court.

She will have an MRI scan but hopes to play at the Miami Open - the second half of the 'Sunshine Double' that follows Indian Wells this month.

Belarusian world number one Aryna Sabalenka hit 23 winners as she beat Romanian Jaqueline Cristian to set up a fourth-round meeting with Japan's Naomi Osaka, who defeated Colombian Camila Osorio 6-1 3-6 6-1.

Osaka, a four-time Grand Slam champion, is playing her first tournament since withdrawing during the Australian Open in January with an abdominal injury.

Italian world number two Jannik Sinner beat Canadian Denis Shapovalov 6-3 6-2 to reach the men's fourth round.

Sinner will face rising Brazilian star Joao Fonseca, who advanced to the fourth round of a Masters 1000 event for the first time with a 6-2 6-3 win over American Tommy Paul.

German fourth seed Alexander Zverev held off American Brandon Nakashima 7-6 (7-2) 5-7 6-4.