Police were called to a house in Delta Walk, Moston, at 10.20pm on Sunday.
Officers discovered the body of a 41-year-old man who had been stabbed.
A 13-year-old girl suffered serious injuries, also believed to be stab wounds, and was taken to hospital where she is in a critical condition.
Just before 1am, police were called to Watfield Walk in Harpurhey after a man threatened a car owner with a knife and stole a vehicle.
A short time later, the vehicle was seen by police near Rochdale Road. When officers approached, a 34-year-old man drove the car into the side of the Alliance pub.
He was taken to hospital suffering from a stab wound and injuries consistent with a collision but died a short time later.
No one else was injured in the smash.
More top news
Microsoft's new system Windows 10 has been met with approval after its disastrous predecessor but users have yet to be entirely convinced.
Alton Towers crash victim Leah Washington, who lost a leg as a result of the horrific incident, celebrated her 18th birthday last night.
American Football's first female coach, Jen Welter, is hoping to be an inspiration across the globe after being hired by Arizona Cardinals