(CNN) -- Portugal football legend Eusebio, who was top scorer at the 1966 World Cup, died at the age of 71, his former club Benfica said Sunday.
He died from a heart attack, the Lisbon side said on its website.
The striker, affectionately known as the "Black Panther," was admired throughout the Portuguese-speaking world and was thought to be among the sport's greatest players.
"Always eternal #Eusebio, rest in peace," Real Madrid forward and current Portugal icon Cristiano Ronaldo tweeted alongside a picture of both men together.
Portugal's former world player of the year, Luis Figo, tweeted that Eusebio was the "king" while Brazil's Pele, considered by many to be the best footballer of all time, tweeted that Eusebio was like a "brother" to him.
"May God receive him with open arms," said Pele.
Eusebio, whose full name was Eusebio da Silva Ferreira, played for three North American Soccer League teams in the twilight of his career but is best known for his exploits in 15 years at Benfica.
Born in 1942 in Mozambique, which was then a Portuguese territory, he scored 41 goals in 64 appearances for his adopted country.
Named European Footballer of the Year in 1965, Eusebio won widespread acclaim the following year at the World Cup in England. He scored nine goals in the competition, helping his team reach the semifinals.
World Cup scorer
He scored two goals as Portugal eliminated defending champions Brazil in the group stage, then netted four times in an incredible quarterfinal comeback against North Korea as his side rallied from 3-0 down to win 5-3 in one of the tournament's most famous matches.
Eusebio scored again in the semifinals against England, but the hosts won 2-1 before beating Germany in the final.
"His talent brought joy for entire generations, even those who didn't live through the most glorious moments of his career," Portuguese President Anibal Cavaco Silva told Portuguese television.
World football body FIFA said Eusebio was considered "one of the best footballers of all time and best ever from Portugal."
"Football has lost a legend," FIFA president Sepp Blatter tweeted as the tributes continued. "But Eusebio's place among the greats will never be taken away."
Added UEFA president Michel Platini: "On the field, Eusebio was a true legend, both in the colors of Portugal and Benfica," he told UEFA's website.
"But also off it, he was a true ambassador for Portuguese football on the international stage. He was more than a footballer. A good and charming man, Eusebio will be sadly missed."
During his career with Benfica, the Lisbon side won the European Cup in 1962. He scored 733 times in 745 professional matches, according to FIFA.
He won 10 league titles and five Portuguese cups with the Eagles and was Portugal's top league scorer between 1964 and 1973.
"We're saddened to hear Benfica legend Eusebio has passed away," tweeted Manchester United. "He was a fantastic player and a friend of the club."