Dominic Thiem slumped to a sensational defeat to the No.222-ranked Ramkumar Ramanathan in the second round of the Antalya Open, while Novak Djokovic was frustrated by the rain at the Aegon International.

Thiem lost to Robin Haase in the second round of Gerry Weber Open and will head to Wimbledon on the back of a shock exit to Indian outsider Ramanathan on the grass in Turkey.

The No.1 seed was given a first-round bye, but could go no further than the last 16 after going down 6-3 6-2 in just shy of an hour.

Qualifier Ramanathan blasted down 10 aces and broke the world No.8 eight three times to move into the quarter-finals on Wednesday (AEST).

Thiem's first serve percentage was as low as 48 and he did not manage a solitary break of serve in a one-sided match, so the Austrian now has the option of an earlier arrival in London for the third grand slam of the year.

There was no such trouble for No.3 seed Fernando Verdasco, who defeated Steve Darcis 6-3 6-4. Marcos Baghdatis and Adrian Mannarino also made it through the quarter-finals.

Carlos Berlocq saw off Viktor Troicki in the first round, while Andreas Seppi, Daniel Altmaier, Janko Tipsarevic and Marsel Ilhan also reached the second round.

Djokovic was left kicking his heels for much of the day at Eastbourne, where heavy rain meant less than 10 minutes of play was possible.

The world No.4 won the first game of his match against Vasek Pospisil and led 30-15 in the Canadian's first service game when the covers came on.