Heather Watson: British number two loses to Kristina Mladenovic in Mexico
Britain's Heather Watson lost 7-6 (7-4) 6-7 (5-7) 7-5 to France's Kristina Mladenovic in a three-and-a-half-hour battle at the Abierto Mexicano Telcel.
The 24-year-old finally succumbed to Mladenovic, ranked 43 places higher in the world rankings at 30th, with her 18th double fault of the match.
A see-sawing match featured 15 breaks of serve, with Watson converting seven of her 14 chances.
Second seed Mladenovic will play Kirsten Flipkens in the third round.