With the score tied 2-all with two outs at the bottom of the last inning, Saipan slugger Mariano Lisua hit a grounder to center to score Vince Zablan from third base.
However, Lisua did not complete the run to first base, joining his teammates and coach celebrating and hugging on the field.
The pitcher threw to first base and Lisua was out, annuling the game-winning run.
The Guamanians, cashing in on the low spirits of their opponents, went on to score four runs in extra inning to win the game.
It was a tragic end to what could have been a bright campaign for the Chamoros who tied the score in the sixth inning on a solo homerun by second baseman Shane Yamada.
With no out, they had the chance to win the game, the crown and the chance to represent the region in the Little League World Series in Pennsylvania.
Then came the unexpected.
Jesus Borja and Joshua Ariola struck out in the next play. Zablan strode to the plate, hit a single and stole second and third for a scoring position.
Lisua hit a grounder to centerfield, driving home Zablan.
All the players, including their coaches, cheered and rushed to the field to celebrate. Lisua, carried away by the celebration, went back to join his teammates and was eventually called out for not completing the run.