British number two Heather Watson suffered "one of the worst" losses of her career as she went down 3-6 6-0 12-10 to Annika Beck at Wimbledon.
Watson, 24, failed to convert three match points in a dramatic final set as Germany's Beck triumphed in two hours and 52 minutes to reach round two.
The pair had resumed their rain-delayed match from Wednesday in the third set.
"I wasn't pleased with the match in general, how I played," said Watson, ranked 55th in the world.
"Having match points in the match, not being able to win here at Wimbledon, is the worst. I take losses badly anyway, but this is one of the worst."
Watson's serve was broken twice early in Thursday's final set but she went on to win four consecutive games to level.
After Watson wasted her match points, world number 43 Beck found the elusive break in the deciding set, which lasted one hour and 44 minutes.
Watson, who will compete in the doubles alongside compatriot Naomi Broady, said she had received "plenty" of online abuse following her defeat.
"I was just in the changing rooms with Naomi Broady and Tara Moore talking about it," she said.
"After a loss like this, I'm so angry with myself I feel like I need to punish myself. It wasn't a good day. I just went on Twitter. There was plenty."
Asked if she felt women players were targeted more than men, Watson added: "I'd say it's more women. I don't know why they bet on us because our results are all over the place. First of all, that's not very smart from them."
Watson, from Guernsey, has won three WTA titles and reached a career-high ranking of 38 but has yet to make it past the third round of a Grand Slam.
"I feel that I'm a lot better player than this, but my ranking doesn't lie," she said.
"I'm obviously lacking in areas. I just need to go back to the drawing board and keep trying and improving, because I really do believe that I can do a lot better than I have done in my career so far."
Jo Durie, former British number one and 1984 Wimbledon quarter-finalist
"It is a crushing defeat for Heather. When you have three match points in a row you think you're going to win one of them.
"But she got a little bit too passive and allowed Annika to take advantage. She was so devastated after not taking one of those opportunities, it was basically the end of the match.
"It was a difficult match because they are both similar players who like to counter-attack. Heather was trying to be more aggressive but missed too many at the wrong moments. She didn't have the boldness of play when she needed it."