Defending champion Heather Watson beat Serbia's Nina Stojanovic in three sets to reach the second round of the Monterrey Open in Mexico.
Watson, 24, fought for two hours and 52 minutes to register a 6-2 6-7 (7-9) 6-4 victory over the world number 126.
The British number three smashed her racquet in frustration after squandering two match points in the second set tie-break.
She will face Russian sixth seed Ekaterina Makarova in the second round.
Watson, currently ranked 125th in the world, led the second set 5-2 before Stojanovic hit back to force a deciding set.