Portuguese football legend Eusebio, who was the top scorer in the 1966 World Cup, died Sunday at the age of 71 years, his former club Benfica confirmed.
Regarded as one of the greatest footballers of all time, the player known as the "Black Panther", died after suffering cardio-pulmonary arrest early on Sunday morning.
He had been hospitalised several times in recent years with various health problems and had suffered a stroke in June 2012.
"Eusebio showed signs of fragility lately, but I didn't expect this at all," said Joao Malheiro, author of the player's biography "Eusebio - my story", who had spoken to him last week by phone to arrange a lunch.
The player's remains will be transferred during the day to the Luz stadium in Lisbon where Benfica fans can pay their final respects to their greatest star, public television station RTP reported.
"The king! Great loss for all of us! The greatest!" wrote former Portuguese international Luis Figo, who retired in 2009 with a national record of 127 caps, while current Portugal captain Ronaldo wrote: "Always eternal #Eusebio, rest in peace."
The Mozambique-born striker made his name at Benfica, winning 11 league titles and one European Cup during a 15-year spell there. He also won two Golden Boot awards as Europe's leading goalscorer.
Recruited aged 19 by the Lisbon club for his exceptional technical and physical qualities he helped the club win the 1962 European Cup against the Real Madrid of Argentine legend Alfredo Di Stefano.
"He was not only one of the greatest figures of football but also of Portugal. Eusebio is Portugal," Chelsea's Portuguese coach Jose Mourinho told RTP.
"I grew up with Eusebio and Amalia Rodrigues (singer who died in 1999), ... as the great symbols of Portugal. They are simply immortal," he said.
"There are princes of football but Eusebio was in the gallery of kings," former Benfica coach Toni told TSF radio.
Eusebio won 11 league titles and five Portuguese cups in his 15 years at Benfica and was Portugal's top league scorer between 1964 and 1973.
He scored 733 times in 745 professional matches.
Despite his scoring record, however, his only appearance at a World Cup finals was in 1966 in England.
"I was the best player in the world, top scorer in the world and Europe. I did everything, except win a World Cup," Eusebio said in a interview in 2011, recalling his tears after Portugal's loss in the 1966 World Cup semi-final to England.
He helped Portugal however take third place in the tournament, where he was top scorer with nine goals.
Tributes also flowed in from former players including Alex Stepney, the former Manchester United goalkeeper, who famously saved a late shot from Eusebio during the 1968 European Cup final at Wembley.
"I made the save and out of the corner of my eye I saw him still standing in front of me. It was only afterwards that I saw what he had done. The fact he was standing there clapping before running away is a mark of the man," Stepney said.
"I was lucky enough to meet him a few times since that 1968 European Cup final and he was the perfect gentleman."
Spanish club Real Madrid said in a statement: "Real Madrid are sad to learn about Eusebio's death, one of the greatest players of all time.
"The club would like to send its condolences to his family, friends, Benfica and Portuguese football in general."