Britain’s Emma Raducanu suffered another early exit as she was beaten by Katerina Siniakova in the second round of the Miami Open.

Raducanu served for the match in the third set but ultimately lost 3-6 6-4 7-5 to the erratic Czech.

The US Open champion, 19, has won just two of her seven matches this season.

Earlier, compatriot Heather Watson claimed her first win over a top-20 player since 2020 with a 4-6 6-3 7-6 (7-4) victory over Elina Svitolina.

Watson saved a match point on her way to victory over the 20th-ranked Ukrainian.

It is the first time in six years that Watson has reached the third round in Miami.

“I love this tournament. I’ve been coming here for so long, I feel like it’s home,” Watson told Amazon Prime.

Andy Murray begins his campaign later on Thursday against Argentina’s Federico Delbonis.

Raducanu, seeded 11th, will be left to rue her missed chances – she converted just five of 17 breakpoints and looked to be affected by nerves as she attempted to serve out the match.

She started the stronger of the two and raced to a 4-1 lead, with a tearful Siniakova taking a medical time-out for what appeared to be a rib problem.

After closing out the first set, Raducanu raced to a break lead in the second before the world number 53 forced a decider.

Raducanu again took a break lead early in the third set and had a chance to go 3-0 up before Siniakova reeled off three games in a row.

Despite this, Raducanu broke and served for the match at 5-4, but a double fault handed the initiative back to Siniakova.

The Czech, ranked number one in women’s doubles, was then able to take advantage of a visibly disappointed Raducanu to close out victory.