Cameroon played a man down from the 71st after defender Ghislain Mvom was red carded.
Earlier, Uruguay outplayed New Zealand from the start but was held 1-1.
Andrew Bevin took advantage of one of New Zealand's only chances to score with a header in the 57th, but Adrian Nicolas Luna equalized for the Uruguayans in the 74th with a right-footed shot into the far corner after a well-crafted attack.
Uruguay had 58 percent of the possession and outshot New Zealand 25-8 at the Pascual Guerrero stadium, but New Zealand goalkeeper Stefan Marinovic made several key saves.
''We deserved better luck,'' Uruguay coach Juan Verzeri said. ''Their goalkeeper stopped everything.''
Uruguay will finish group play against Cameroon, while New Zealand will face Portugal.
''I'm satisfied with the team's performance, but not with the result,'' New Zealand coach Chris Milich said. ''We earned our first points in the World Cup but we didn't come here to draw matches, we want to win them.''