Punjab took an early lead but Mumbai rallied from the setback to be 2-1 up going into the fourth and final quarter before a concerted Punjab attack struck twice in the space of three minutes to surge into a 3-2 lead.
Later, Dharamvir Singh struck in the final minute for his second goal to complete the tally.
The goal scorers for Punjab were Dharamvir (2), skipper Jamie Dwyer and Ranjit Singh