Bystanders begged a dying man to "please stay with us" after he was "deliberately" struck with a car outside a party, witnesses have said.
Emergency services were called to Stonyhurst Road in the Woolton area of Liverpool after the 47-year-old was injured at 23:45 BST on Friday.
Police said a 41-year-old man had been arrested at the scene on suspicion of murder and remained in custody for questioning.
Resident Yvonne Sowerby, 65, told the BBC "it didn't seem real" after witnessing the aftermath of the attack yards from her front door.
"You can't get your head around it, you don't expect it anywhere but especially not here," she said.
Ms Sowerby said earlier in the evening she had seen a number of guests carrying presents and "party bags" into a house belonging to a woman who had moved to the area relatively recently.
At about 23:30 she described hearing a "commotion" outside, which appeared to die down before flaring up again.
"Something made me jump out of bed, I don't know whether it was the screech of brakes or what," she said.
"I saw a car diagonal across the road. On the other side of the car was a group of people looking down so I gathered somebody was lying in the road.
"They were shouting at him, 'Stay with me, stay with me. Don't you dare close your eyes. Please, please stay with me'. We heard all that while we were standing there."
Another neighbour described hearing a woman shouting "that's my brother" as she ran to where the injured man was lying.
Witnesses who saw the aftermath also described the driver's side door being left open on the car.
On Saturday, a large blue inflatable police tent had been placed around the black car that struck the victim as well as a white van in the middle of Stonyhurst Road.
Detectives could also be seen knocking on doors and speaking to local residents.
Det Insp Katie Coote said that while the police investigation was at an early stage, it did "appear the car was deliberately driven at the man".
She added: "Our officers are continuing to carry out inquiries at the scene and studying CCTV footage to establish the full circumstances.
"I appeal to anyone who witnessed this incident and any residents living locally who might have CCTV showing the incident, to please get in touch."
Merseyside Police said local residents had rushed to help the injured man before paramedics arrived.