Dale Caven, 28, fell into a door and staggered along the street shortly before he approached the teenager who was stood outside her home.
A court heard he asked the girl how old she was and if she had a boyfriend before repeatedly asking for a hug.
The teen refused but Caven grabbed hold of her by putting both his arms around her and tried to kiss her.
She eventually managed to escape his grasp and ran inside her home in Stoke-on-Trent, Staffs., where she called police.
Caven, of no fixed address, pleaded guilty to carrying out the sexual assault as well as two separate matters of a public order offence and being drunk and disorderly.
Magistrates jailed him for 12 weeks when he appeared at North Staffordshire Justice Centre on Wednesday (6/7).
Caven was also ordered to pay £50 compensation to the victim and a £115 victim surcharge.
The court heard the teenage girl was left struggling to breathe after she was sexually assaulted by a “clearly drunk” Caven on May 18.
Prosecutor Steve Knowles said: “Mr Caven asked the injured party questions about how old she was and whether she had a boyfriend.
“She told Mr Caven she was 16 and she had a boyfriend.
“He said he should be her boyfriend. He kept asking her for a hug, which was refused.
“However, he grabbed hold of her, putting both arms around her.
“She folded her arms to protect her breasts as she thought he might try to touch them.
“He asked for a kiss. This was refused. He then tried to kiss her while still holding her.
“This caused her to struggle to breathe.”
The court heard on the same day police were called to a report of ambulance staff struggling to deal with a male who was later identified as Caven.
Mr Knowles added: “Mr Caven had to be handcuffed because he was trying to hit himself and officers.
“Officers eventually managed to get him into the ambulance to be assessed.
“He was shouting.
“Officers released the handcuffs but had to reapply them because the officer said he was kicking out at her.
“He was told to calm down. He continued his behaviour and was arrested.”
The court heard Caven had a problem with alcohol, drinking five to six bottles of Lambrini a day, and had been smoking the drug Black Mamba.
He told police his recollection of the sexual assault was “hazy”.
Nick Ryles, defending, said: “He accepts that in the weeks and months leading up to this his life was spiralling out of control, due to his alcohol misuse and misuse of Black Mamba.
“At the time of his remand he was living in a garden shed at his mother’s.
“His difficulty is he doesn’t have an address to be released to.
“He’s extremely remorseful for his actions on that day, although he has no clear recollection.”