Giovani Leituala scored a try and kicked the winning penalty to help King's High School beat John McGlashan College 10-8 in the final of the Otago Premier Schools competition.
Markham's College won both its final round-robin games on Saturday to top the premier A competition and book a semifinal against St Hilda's Collegiate A.
The Stampede will head to Christchurch safe in the knowledge it needs only one point from its two remaining round-robin games to secure home advantage for the final series.
The Otago Rugby Football Union has confirmed it will hold a judicial hearing following a misconduct complaint stemming from an incident in a colts game late last month.