In just their first season, the club began playing in the Peruvian top-flight, the Torneo Descentralizado, after they bought the promotional place of the 2003 Segunda División winners, Sport Coopsol.

Despite not finishing in the top 6 places in the Clausura tournament, thereby not fulfilling the condition to qualify for the national title playoff, the Clausura winners Coronel Bolognesi had not satisfied the condition in the Apertura either, so no playoff was played and San Martín were awarded the national title on the basis of its better aggregate record throughout the season.

On 20 February 2012, the club Universidad San Martín, for extra-sporting issues, announced their definitive retirement from the local tournament and professional football.

[1] On 14 March 2012, the club Universidad San Martín returned to the local tournament and professional football.

5/8 Liguilla "B" Alemanno 41' Note: Flags indicate national team as defined under FIFA eligibility rules; some limited exceptions apply.