Reigning men's champion University of Santo Tomas and defending women's titlist De La Salle University start their title retention bid Saturday in the opening of the UAAP Season 73 badminton event at the Rizal Memorial Badminton Hall.

Competition formally starts at 9 a.m. following a brief and simple opening ceremony, which ushers the league's second event in the first semester calendar.

The Tigers will take on Adamson at Court 1 in the first match while three other games will be held simultaneously in three other courts.

De La Salle University faces National University in Court 2, Ateneo de Manila tangles with Far Eastern University in Court 3 while University of the Philippines and University of the East square off in Court 4 for the men's action in the morning.

Action resumes at 1 p.m. with the scheduled four matches in the women's division.

The Lady Archers begin their back-to-back title hunt when they tackle the Ateneo Lady Eagles in Court 1 while UE Lady Warriors will go up against the National University Lady Bulldogs in Court 2.

FEU Lady Tamaraws face UP Lady Maroons in Court 3 and Adamson Lady Falcons go up against UST Tigresses in Court 4 in the other pair of matches in the women's category.