South Africa's Brazilian coach Carlos Alberto Parreira said Forlan was the outstanding performer of a Uruguay side that outplayed his team with their big game experience as they look to revive some of their past glory.
"Forlan is a striker who makes a difference, we've known him for many years back in Brazil," Parreira told the post-match news conference.
"He's a player who if you don't keep an eye on him he will damage you," he said of the striker who put Uruguay ahead with a shot from outside the box that took a slight deflection midway through the first half.
"Forlan made the difference with his first goal..If they had not scored the first goal I think the match would have been very different," Parreira said.
"We know we played a good game, that we defended well and took our chances," he told a television interviewer.
"We knew this was a difficult group. It's all very even," he added of a group which also includes France and Mexico, who meet in their second match on Thursday.
"We've got to go step by step and think only of the next match," he said.
