Monterrey Open: Heather Watson beaten by Angelique Kerber
Heather Watson's Monterrey Open title defence ended in the quarter-finals as she lost 6-4 6-4 to world number one Angelique Kerber.
The 24-year-old British world 125 could not convert any of her eight break points and lost in one hour 23 minutes.
Kerber seized upon her only break point of the first set to lead 4-3 and again in the opening game of the second.
The German now plays Spain's Carla Suarez Navarro, while Caroline Garcia plays Anastasia Pavlyuchenkova.