Tennis: Britain's Heather Watson celebrates her first top-10 win

INDIAN WELLS, California (REUTERS) - Britain's Heather Watson pulled off her first victory over a top-10 ranked player with a 6-4 6-4 upset of Agnieszka Radwanska in the third round of the BNP Paribas Open on Sunday.

The 22-year-old Channel Islander broke the Polish world number eight in the opening set, then stormed back from 2-4 down in the second by winning four games in a row to end the match after an hour and a half.

It was the first time Watson had taken a set off Radwanska, having lost in their three previous meetings, most recently in the second round at Indian Wells last year. "She's a great player," an elated Watson, ranked 43rd, said courtside of the seventh seed after serving out for the match to love on another hot day at the Indian Wells Tennis Garden. "I knew I would need my 'A' game today." British number one Watson had made a fast start to the year, winning her second WTA career title at the Hobart International in January, but then struggled as she failed to advance beyond the opening round in her next three tournaments.

Watson will next face either Spaniard Carla Suarez Navarro or Russian Anastasia Pavlyuchenkova, who were playing later on Sunday.

In other third round matches, American world number one Serena Williams was due to take on Kazakhstan's Zarina Diyas before third-seeded Romanian Simona Halep faces American Varvara Lepchenko in an evening encounter.