Substitutes Hamed Mabaui and Roel Viva joined the act with goals in the 86th and 87th minute marks, respectively, for Union, which pounced on the sending off of Dolphins striker Greg Calawod 22 minutes into the second half.
Handled by Uruguayan coach Maor Rozen, Union paraded two promising teenage players in winger Ken Guevarra from Bago City and Papu Corsame from Tondo, who caused problems to the Dolphins defense.
In a Group B clash, Sammy Fogg scored two goals as Nomads fought back from a goal down to crush Inter Manila, 4-2, and clinch a quarterfinal berth.
Fogg cancelled out Sterlin Whitcomb’s 24th minute goal with his own marker in the 25th minute, before netting his second at the stroke of halftime.
With their third win, the Nomads have nine points from four matches to take top spot in their group ahead of the Stallions, who have seven points from three games.
In a battle of eliminated teams, Japan FC erased a two-goal deficit in the second half and came away with a 3-2 win over Green Archers Orient Freight.