Reeshard has been officially cleared by the Court of Arbitration for Sport, which dismissed WADA and the ITF's appeals.
The court accepted Gasquet's claim that he inadvertently consumed cocaine by kissing the woman in a Miami club hours after withdrawing injured from a tournament in March.
"It was impossible for the player, even when exercising the utmost caution, to know that in kissing a woman who he had met in a totally unsuspicious environment, he could be contaminated with cocaine," the court said in a statement.
A CAS panel of three lawyers said the quantity of the drug in Gasquet's urine test was "minute" and the 23-year-old Frenchman was "clearly not a regular cocaine user."
"The possibility of contamination became the most plausible explanation," CAS said.
The verdict was greeted with dismay by WADA and the ITF, the sport's world governing body.
"WADA considered that the evidence warranted full and total scrutiny," director-general David Howman said in a statement. "WADA abides by the CAS ruling and has no further comment at this stage."
ITF president Francesco Ricci Bitti said the federation was "disappointed" with the court's ruling.
"The ITF also recognizes the potential implications of the CAS decision with respect to future decisions and will discuss these with WADA," he said.
The 23-year-old Gasquet served a 2 1/2-month suspension before an independent ITF tribunal cleared him to resume his career in July. It ruled he was not to blame because the woman -- identified only as "Pamela" -- contaminated him with cocaine.
CAS said that ban should not count as a doping offense on Gasquet's record, even though he had not appealed against it.