French player Alize Cornet has avoided a potential ban after the International Tennis Federation dismissed a charge against her for missing three drugs tests in a year.
Players must be available for out-of-competition testing for one hour every day under the whereabouts rule.
Cornet, 28, said her intercom buzzer was broken during the third attempt.
An independent tribunal found the doping control officer did not take "reasonable steps" to locate her.
The world number 32 said she was inside her apartment during the designated time slot, but did not receive an intercom call or a phone call.
She also pointed out she had never tested positive in over 100 tests during her career.
The tribunal said it accepted Cornet's "frank and compelling" evidence.
"No-one has suggested any basis for thinking she has ever taken any form of prohibited drug," it added.
Cornet said she missed the first attempted test, on 3 November, 2016, after leaving early for a flight to a competition because she was "afraid of missing her flight due to traffic".
She had also already left her home in Cannes for the Stanford Classic in the United States at the time of the second attempted test on 26 July, 2017.
Cornet was successfully tested twice in March 2017, and again on 11 October, before the third missed test took place on 24 October.