“It hasn’t been easy, I didn’t want the time to come, but I knew it was going to come,” Forlan said.
Forlan’s former Uruguay team-mate Luis Suarez posted a tribute to him on social media.
“I will always be grateful for what you taught me, both on and off the field. A dream to have played with one of my idols. You will always be a legend in Uruguay.”
Forlan’s memorable moments
He netted in the 64th and 67th minutes – the first courtesy of a howler by home keeper Jerzy Dudek – to secure a 2-1 win over United’s Premier League rivals.
Forlan may well be best remembered for celebrating – rather than scoring – a goal for United.
Coming on as a 79th-minute substitute, the then 23-year-old smashed in a brilliant shot to seal victory over Southampton in November 2002.
He ripped off his shirt in celebration – but was unable to put it back on before the game restarted and played on topless, even making a tackle.
A Uruguay great
With Uruguay, Forlan was a Copa America champion in 2011, while he also won the Golden Ball – awarded to the tournament’s best player – at the 2010 World Cup as they finished fourth.
He is Uruguay’s third-highest goalscorer – netting 36 times in 112 caps – behind Suarez and Paris St-Germain’s Edinson Cavani.
He retired from international football in 2015.