Russian tennis star Maria Sharapova hailed the reduction of her two-year doping ban as one of the “happiest days” of her life, immediately targeting a return to action in April 2017.

The Lausanne-based Court of Arbitration for Sport (CAS) cut to 15 monthsSharapova's ban imposed by an independent tribunal appointed by the International Tennis Federation for testing positive for meldonium.

The 29-year-old tested positive for the banned medication meldonium during January's Australian Open, throwing her glittering career — 35 WTA singles titles and more than $US36 million in career earnings — into serious jeopardy.

In its verdict, the CAS “found that Ms Sharapova committed an anti-doping rule violation and that while it was with ‘no significant fault', she bore some degree of fault, for which a sanction of 15 months is appropriate”.