Tindall James and Jonty Clarke scored two goals for Great Britain in the first half of the match followed by two goals from Ashley Jackson on penalty corners in the second half.
The Pakistan team looked totally out of form and players were unable to repeat their best performances as done in the early two matches against Argentina and Spain. Veteran penalty corner specialist Sohail Abbas scored the lone goal for Pakistan in the last minute of the match.
Pakistan will play their fourth Olympic match against South Africa on Sunday at 10:45am PST.
Pakistan started their Olympic campaign with a 1-1 draw against Spain and a 2-0 victory against Argentina.