The Lausanne-based Court of Arbitration for Sport (CAS) said it had rejected an appeal from Viitorul's rivals FCSB, formerly known as Steaua Bucharest, who had protested over the rules of the competition and claimed they were the rightful champions.
The two teams finished level on 44 points but Viitorul took the title by having the better head-to-head record during the six-team final stage of the championship.
FCSB argued that the head-to-head record should have also taken into account the two matches played in the regular championship, in which case they would have won the title.
CAS said in a statement that it had "confirmed the standings that were ratified by the Romanian Football Federation's Executive Committee on June 5."
"Accordingly, FC Viitorul is confirmed as the first-placed team and FCSB is confirmed as the second-placed team."
Hagi, nicknamed "The Maradona of the Carpathians" and considered Romania's all-time greatest player, founded Viitorul in 2009 and still owns the club, known for nurturing young talent in the Black Sea state.
Both teams will enter the Champions League in the third qualifying round, although Viitorul will go into 'champions' half of the draw which is theoretically easier. (Writing by Brian Homewood; Editing by Ken Ferris)