Cilic to return after appeal
Marin Cilic has been cleared to play in next week's Paris Masters after his doping ban was reduced from nine months to four.
The 25-year-old Croatian tested positive for the banned stimulant, nikethamide, at the BMW Open in Munich in May.
Cilic claimed he did not intend to ingest the substance in glucose tablets and challenged his ban at the Court of Arbitration for Sport.
The International Tennis Federation also appealed the verdict of its own independent tribunal and requested a two-year ban for Cilic from CAS.
However, CAS upheld Cilic's appeal and decided the ITF sanction was "too severe".
"The panel determined that the degree of fault committed by the athlete was inferior to that established in the (tribunal) decision," the court said in a statement.
"The panel also determined that the sanction imposed was too severe in view of the degree of fault and concluded that it should be reduced to four months."
Cilic, who has dropped from 12th to 47th in the world rankings since accepting a provisional suspension in June, is free to play again from midnight on Friday.