The man was left for dead following the brutal assault by a gang of teenagers at the Freehold Metrolink stop in Oldham.
Detectives said the yobs ‘played to the audience’ after a tram stopped on the opposite side of the tracks .
They walked off, only to return to continue the attack, three times.
The violence was described by Metrolink bosses as ‘indiscriminate and wanton’.
Police are treating the vicious attack, which left the 49-year-old badly injured, as attempted murder.
The three thugs - aged between 15 and 18-years-old - jumped the man at the Chadderton stop at around 9.30pm on March 8.
They continued to attack him as he lay unconscious on the floor in a pool of blood.
Metrolink cameras captured the horrific assault.
Graphic footage shows the thugs attacking the man. At one point, one teenager can be seen dragging the man by the leg across the floor before stamping on him.
Some of the video had to be cut as it was so distressing.
Police say the man was hit, punched and stamped on more than 100 times.
The victim was left with a bleed on the brain - and a fractured cheek, nose and ribs. Doctors thought he would lose an eye, but it has been saved.
GMP said the thugs ‘played to the audience’ and continued beating the defenceless man while he was unconscious.
It wasn’t until tram passengers pulled the emergency cord to open the doors that the teenagers fled.
The Metrolink driver also jumped out to try and help.
Police said the driver and passengers’ brave actions saved the man’s life.
Paramedics attended and rushed the victim to hospital. He has been left traumatised by the attack.
Police said the three teenagers were all male, Asian and of slim build. They were wearing bubble jackets and trainers.
Detective Sergeant John Coleman said the attack, which lasted for four minutes, was the worst he had ever seen.
He said the victim had been out with his partner and friends in town and had gone home as he had work the next day.
Moments before the attack he had messaged his partner to say he had arrived at Freehold.
DS Coleman said: “Not only did these men target an innocent man for no apparent reason, they subjected him to a sustained and brutal attack and the footage is absolutely shocking.
“How anyone could kick a defenceless man in the head as he lay unconscious is almost unbelievable, but for them to return on three separate occasions to continue their assault and then leave him bleeding on the platform is beyond comprehension.
“The fact the victim not only survived, but is now on the road to recovery, is pretty incredible.
“We know a tram stopped on the opposite side of the tracks at the time of the attack and I would urge anyone who has any video footage to please send it in to us as a matter of urgency. It could be vital to finding the people responsible.
“Alternatively, anyone who thinks they know who did this, or has any information, please get in touch. This could have been your father, son or brother and we need to find these men immediately.”
Transport for Greater Manchester’s head of Metrolink, Danny Vaughan, said: “This was a sickening and sustained attack that has left a man seriously injured.
“We know there’s been a spike in the number of incidents of crime and antisocial behaviour in the Oldham area recently.
“It is something we are working with partners to try and tackle but the extent of this assault and level of force used was indiscriminate and wanton.
“Working under the TravelSafe Partnership the number of patrols in the area has been increased significantly and CCTV of the incident has been handed over to police to assist their investigation. I’d encourage anyone with information about this incident or those responsible to come forward.”
A witness to attack has told the Manchester Evening News: “The victim did not seem to be moving and many passengers presumed he was dead.
“The tram driver had already left the platform before stopping the tram again to shout at the offenders, however they ignored this and continued to viciously assault the victim.
“Many of the passengers screamed from the tram for the thugs to stop, however they continued.
“This attack lasted approximately five minutes, all whilst the victim lay on the floor motionless.
“It was only when one of the passengers pulled the emergency door release lever on the tram that people were able to leave the tram to attend to the victim, it was at this time the tram driver closed the doors of the tram and left the Freehold tram stop.”
Anyone with information is asked to call police on 0161 856 8267, quoting reference number 2239 of March 8.
Reports can also be made to Crimestoppers, anonymously, on 0800 555 111.