Johanna Konta has been knocked out of the Qatar Open at the last-16 stage by Angelique Kerber.
The British No 1 raced through the first set but was unable to build on her promising start as Kerber responded to secure an emphatic 1-6 6-1 6-3 success.
The German’s reward for seeing off the 10th seed is a quarter-final meeting with Caroline Wozniacki.
The world No 1 progressed to the last eight in a feisty match against Monica Niculescu where she complained about – and apparently mocked – her opponent’s grunting.
The recently crowned Australian Open champion won 7-5 6-1 against the Romanian but was visibly agitated in the ninth game of the first set, when she complained that her opponent was making noises as the Dane was about to hit the ball.
Wozniacki was so upset about the sounds coming from the other side of the net that she complained to French umpire Emmanuel Joseph.
“It isn’t in the rule book that you are not allowed to grunt when the opposing player hits?” courtside microphones caught her asking Joseph.
The umpire said he thought everything was “regular”, but Wozniacki added: “It’s the only way she can win.”
She then mimicked the grunts and afterwards complained that her opponent was “a player that tries to get into your head”.
She also told Danish TV that her opponent had used “unfair methods”.
“[I] just tried to let him know to pay attention to her grunting because she’ll hit the ball and two seconds later when the ball is on my side and I’m right about to hit, she’ll start grunting and make a noise,” the Dane told reporters.
“And she will change the grunt according to what she feels like.”
Asked if she thought her opponent was grunting deliberately, Wozniacki responded: “I think that she didn’t do it in the second set, so…”
The spat overshadowed a relatively routine victory for the 27-year-old, which ensured she retained her No 1 ranking after Simona Halep also advanced to the final eight.
Halep beat Anastasija Sevastova 6-4 6-3 hitting 29 winners on her way to victory.