Intro:

Heather Watson beats Agnieszka Radwanska 6-4, 6-4 at Indian Wells in California, USA, on Serena Williams beats Zarina Diyas 6-2, 6-0 on Sunday (15th March) at Indian Wells on California, USA.

Script:

Heather Watson has been threatening to do this for a while - beat a top ten player.

But in 11 previous attempts she hadn't managed to do it.

Agnieszka Radwanska her opponent this time and Watson hadn't even taken a set off the world number seven before.

That soon changed as the Brit, ranked at 43 in the world, showed power and accuracy to take it 6-4.

In the second, she trailed 4-2 but reeled off 4 games in a row to take the set and secure perhaps the biggest win of her career.

Andy Murray was watching as he tweeted his congratulations.

Watson will now play Carla Suarez Navarro in round four.

SOUNDBITE (English) Heather Watson, World number 43

"I am very pleased with my performance today. I think Agnieszka (Radwanksa) is a great player. I have played her quite a few times in the past and she has beaten me very comfortably. So I was glad to play well and to get through the match."

But whilst that result may have a shock, the way Serena Williams dispatches lower ranked opponents remains as predictable as ever.

This time it was Zarina Diyas of Kazakhstan, who was making her debut at Indian Wells.

And it was a short one as Serena beat her 6-2 6-0 to progress to the 4th round.

Up next is fellow American Sloane Stephens.