Heather Watson knocked out of Prague Open in first round

Heather Watson
Watson has won 10 matches in 2015

British number one Heather Watson was knocked out in the first round of the Prague Open by Slovenia's world number 72 Polona Hercog.

Watson, who is 40th in the world rankings, lost 7-5 3-6 7-6 (7-5) in a match lasting more than three hours.

The 22-year-old, who won her second WTA title in January, was 3-0 up in the final-set tie-break but was broken three times by Hercog, 24.

Watson also exited her last tournament - the Family Circle Cup - in round one.