The defending champion at Edgbaston, Melanie Oudin, has crashed out of this year's Aegon Classic.
The American, whose only WTA Tour title came 12 months ago in Birmingham, was beaten 6-3 6-1 by Croatian qualifier Ajla Tomljanovic in just 58 minutes.
In cold and windy conditions, the world No 80 was no match for the big-serving Tomljanovic who fired down five aces and won 87% of points on her first serve.
From 3-2 up in the opening set, the 21-year-old from Georgia lost nine successive games to an opponent ranked 75 places below her.
Despite winning last year's final against Jelena Jankovic, Oudin was not seeded on her defence.
Her conqueror, Tomljanovic, 20, now faces top-seed Kirsten Flipkens in the second round.
Tomljanovic said: "My serve was a big factor. I felt really comfortable returning and that meant I could go for more on my serve."