The remark by Mariano Rajoy drew immediate online derision.
Before leaving his Johannesburg hotel for the tribute at Soweto's First National Bank Stadium, Rajoy was asked by Spanish National Radio about the country's "special atmosphere" as scores of world leaders, including U.S. President Barack Obama, were about to join tens of thousands of South Africans in paying tribute to Mandela.
"That football stadium, where Mandela will be bade farewell, is also the stadium where Spain became the world champion playing against Holland, right? So therefore it's really a beautiful moment, full of emotion," Rajoy said.
Because of Spain's 2010 victory in the World Cup Final, "this is one of the most emblematic places in South Africa, and will be even more so in the future, after the events of today," Rajoy added.
His remarks brought immediate condemnation and ridicule on social media and from online news readers in Spain.
"Shameful," El Mundo reader Javier Fortea Pena wrote on the newspaper's website.
"This guy is so, so unfit to be seen that he speaks about the stadium where Spain became the champion in a moment of huge pain for the South African people and for the world in general. Did he go there for the memorial or to do tourism?" reader Ines Maria Romero Invernizzi wrote.
"It's unbelievable his ability to say trivialities in the worst moment," a writer who went by the name of Barbantesa wrote in the Publico online newspaper.
Facebook user Wilhem Everitt Cauer posted a photo showing cartoon character Homer Simpson imagining himself as president.
Spain defeated the Netherlands 1-0 July 11, 2010, 4 minutes from the end of extra time, to win the 2010 World Cup.