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.
Forlan, who has played his club football in Argentina, England and Spain, has often been a thorn in the flesh of Brazil at international level.
"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.
The blond striker added an 80th-minute penalty and midfielder Alvaro Pereira scored the third in stoppage time.
Forlan, one of the leading scorers in European football in recent seasons whose goals inspired Atletico Madrid to the Europa League title in May, was quick to say that Uruguay must keep their feet on the ground after the victory.
"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.
Twice World Cup champions Uruguay, who lead the group with four points following their opening 0-0 draw with France, round off the first round against the Mexicans next Tuesday when a draw will see them into the second round for the first time since 1990.
Follow FFT.com on Twitter
Join FFT.com on Facebook
