A man in his 50s found unconscious at a bus stop was attacked by another man who then fled the scene, police now believe.
Detectives have been trying to piece together what happened after the victim was found with a serious head injury on Wilmslow Road in Withington last Thursday, 12 August.
He remains in hospital in a critics condition.
Following extensive inquiries, police now believe the man was assaulted on Wilmslow Road close the bus stop where he was found at the junction with Victoria Road.
It is believed the attack happened at around 5pm when the road would have been busy with pedestrians and vehicles.
Detectives say the attacker, wearing all dark clothing, fled on foot towards Fallowfield.
Officers are now appealing for anyone who may have witnessed the attack, or have video evidence such as dash-cam footage, to come forward.
Detective Inspector Geoff Machent of GMP's City of Manchester division, said: "We've been following all available lines of enquiry to ensure we establish the full circumstances surrounding this incident and we are now confident that this man was assaulted prior to being found at the bus stop.
"This assault is believed to have occurred around 5pm on a busy road so we're issuing a further appeal to anyone who may have been in the area at the time and witnessed the assault or saw anyone behaving suspiciously, or even anyone who has dash-cam footage, to come forward and speak to police."
"Any information could prove vital to our investigation and could help identify the man responsible for this heinous assault and ensure we can provide his loved ones with the answers that they desperately deserve."
Anyone with information or dash-cam footage is asked to call 0161 856 6063 or 101 quoting incident number 1138 of 13/0/21.
Alternatively, details can be passed by our LiveChat function at www.gmp.police.uk or contact Crimestoppers anonymously on 0800 555 111.
