Two goals in the last six minutes enabled Pakistan to post a 5-4 victory over South Africa in men's Olympic hockey on Sunday, while New Zealand were held to a 1-1 draw by Belgium.
Waseem Ahmed's field goal three minutes from the end clinched victory after captain Sohail Abbas had converted a penalty corner in the 64th minute to neutralise South Africa's lead in the Pool A contest.
The victory took Pakistan's points tally to seven from four matches.
World champions Australia and hosts Great Britain are also on seven points, but are scheduled to play their fourth preliminary league match later in the day.
Abdul Haseem Khan scored two goals for Pakistan in the encounter that saw the lead change hands frequently.
South Africa had earlier ascendency through a second-minute open play strike by Thornton McDade, but Pakistan equalised in the 20th minute on Khan's first goal.
Justin Reid-Ross converted two penalty corners (22nd and 35th minutes) for South Africa, while Shafqat Rasool (23rd) and Khan (25th) fired for Pakistan as the two teams were tied 3-3 at half time.
South Africa seized the lead again three minutes into the second half on Wade Paton's field goal and held sway until the two goal burst from Pakistan in the last six minutes.
"If our strikers play well, we're in the game. The forwards seized the chances," said Akhtar Rasool, chief coach of the Pakistan team.