Livorno midfielder Piermario Morosini died after suffering a cardiac arrest during Saturday afternoon's Serie B match at Pescara, with all this weekend's games in Italy called off in memory of the 25-year-old.
Morosini, who was on loan from Udinese, collapsed in the 31st minute and received treatment on the pitch - reportedly including a heart massage in a bid to resuscitate him - before being rushed to Pescara's Santo Spirito hospital.
The match was abandoned and many players left the field in tears.
Lega Serie B then confirmed on their website: "Tragedy on the field. After suffering a cardiac arrest during the match between Pescara and Livorno, Piermario Morosini has died.
"The 25-year-old player, who came through the youth ranks with Atalanta, arrived at Livorno from Udinese in January and played nine times for the Amaranto."
Quoted on www.gazzetta.it, cardiologist Edoardo De Blasio said: "It was a cardiac arrest. Sadly, he was already dead when he arrived in the hospital and he never recovered."
The Italian Football Association (FIGC) swiftly announced the postponement of all remaining matches in the country over the weekend.
The Lega Serie A said in a statement on their website: "The football world mourns the tragedy that occurred this afternoon in Pescara, where during the game between the hosts and Livorno, the player Piermario Morosini slumped to the ground suffering from a heart attack. Transported to the hospital, the young midfielder was put into an induced coma, but died at around 1700.
"The FIGC has suspended, in memory of Piermario, all games scheduled over the weekend."
The ambulance came onto the field in Pescara to take Morosini away, with both sets of players standing by in distress.
The tragedy comes four weeks after Bolton midfielder Fabrice Muamba suffered a cardiac arrest during his team's FA Cup quarter-final at Tottenham.
The former England Under-21 international was given extensive treatment on the field before being carried off on a stretcher and rushed to the London Chest Hospital.
It took 78 minutes for Muamba's heart to start working on its own again, but he has made incredible progress since.
The Muamba incident invoked memories for many of Cameroon international Marc-Vivien Foe, who collapsed during a Confederations Cup semi-final against Colombia in 2003 and died in hospital.
There have been two similar tragedies with players suffering heart attacks on the pitch in Spain in recent years - Sevilla's Antonio Puerta in 2007 and Espanyol's Dani Jarque in 2009 - while Motherwell's Phil O'Donnell died after suffering a cardiac arrest against Dundee United in 2007.
Roberto Baronio, a former team-mate of Morosini at Udinese, expressed his disbelief to Italy's Sky Sport 24 at the death of his friend.
"He was such a very unfortunate person," he said. "A few years ago, he lost his parents and his brother in such a short space of time. I got to know him when I was at Udinese and there are no words to describe such a chilling feeling. It is absurd - he was just 25 years old.
"When I was at Udinese, he was just coming through the youth ranks and he made his debut that year against AC Milan. You could see he was a hot prospect."
Baronio believes that, given the number of tests professional footballers are subjected to, the tragedy could not have been avoided.
"I think it is just destiny," he said.
"It is not down to the lack of (health) checks because we have so many check-ups and tests nowadays.
"It could happen to anybody. What surprises me is that it happens to a professional footballer. Last year, we had the number of tests increased - every two months we have them. How can this happen? Like Muamba. We cannot understand why. It is destiny which has taken him away."
Bergamo-born Morosini started his career in the youth ranks at his hometown club Atalanta before moving to Udinese in 2005.
A loan spell with Bologna followed before a 2007 switch to Vicenza, where he stayed until returning to Udine two years later. He had further loan stints with Reggina, Padova, Vicenza and finally Livorno.
Udinese owner Giampaolo Pozzo was understandably shocked and saddened by the news, and said his club's players would have been in no fit state of mind to contest tonight's scheduled Serie A game against Inter Milan.
Speaking at a press conference in Udine, he said: "It is one of the saddest days in my career in football. I cannot remember a tragedy like this in my 26 years in the game.
"He was at Udine from 2005, so he was here for six years.
"I remember him as he was a very serious lad, very professional, and he played often away on loan but he was always back here punctually for pre-season.
"This year, we kept him here until January and then we had a large squad so we loaned him out to Livorno.
"This news has hit us hard. The team, when they heard the news, they refused to play today - they said they could not play.
"Ten minutes later, we got the announcement from the FIGC to call off all games. Credit goes to the association for taking this decision so quickly - otherwise we would have taken that decision [not to play], accepting the consequences. There was no way we could have played today after this."