Caster Semenya will not need to take testosterone-reducing medication to compete after a Swiss court temporarily suspended a new IAAF ruling.
The Olympic 800m champion, 28, last month lost her challenge to the Court of Arbitration for Sport (Cas) against the implementation of a restriction on testosterone levels in female runners.
The ruling would have affected women competing from 400m to the mile.
“I hope following my appeal I will once again be able to run free,” she said.
“I am thankful to the Swiss judges for this decision.”
The IAAF said its eligibility rule for DSD athletes will remain in place until they receive official notification from the Swiss court.
In a statement, the governing body said: “We have received no information from the Swiss Federal Supreme Court (SFT) so we cannot comment on these proceedings at this stage and our regulations will stay in place unless, and until, we hear directly from the SFT with an order to the contrary.
“We will continue to fight for what we believe is in the best interests of all female athletes in our sport.”
Semenya took her appeal to the SFT following the decision by Cas, citing the need to defend “fundamental human rights”.
Her legal representative Dr Dorothee Schramm said: “The court has granted welcome temporary protection to Caster Semenya.
“This is an important case that will have fundamental implications for the human rights of female athletes.”
In a statement to BBC Sport, the SFT said it had “super-provisionally instructed the IAAF to suspend the application of the ‘Eligibility Regulations for the Female Classification for athletes with differences of sex development’ with respect to the claimant, until the decision on the request for issuance of provisional measures”.
The South African is set to compete in a 2,000m race in Paris on Tuesday, 11 June, but could instead decide to compete in upcoming Diamond League events in Oslo on 13 June and Rabat on 16 June.