Fighting for fourth spot, Claudio Ciccia's Cartagines claimed an important 2-0 win over Belen Siglo XXI at the Estadio Jose Rafael Fello Meza.
The win saw Cartagines move into fourth, two points clear of UCR – a team not in action over the weekend.
Johan Condega put Cartagines ahead in the 10th minute and Andres Lezcano struck in first-half additional time.
Cartagines have two games to play before the play-offs – if they make it that far – while UCR have just one left.
Deportivo Saprissa remain a chance of finishing second after battling to a 1-0 victory at home to Herediano.
Daniel Colindres scored an 81st-minute winner for the hosts, who are two points behind the second-placed team they beat.
League leaders Alajuelense continued their fine season, winning 1-0 at Limon.
Johan Venegas netted a winner 10 minutes from time as Alajuelense made it 16 wins in 21 Torneo de Invierno matches.