Defendant Carl Alfred Curran, 47, jumped in when he thought his wife Heidi Rowland was being attacked in the Viva Bar, Preston Crown Court heard.
The court heard his wife had been drunk and causing trouble and people had begun to challenge her about her behaviour.
Curran, of Trent Road, Ashton-in-Makerfield, was convicted after a trial of inflicting grievous bodily harm on club guest Julie Hancock in the fracas.
Prosecuting, Wayne Jackson said Curran had tried to pull someone he claimed he thought was a man off his wife and delivered repeated punches after his finger was bitten. The victim lost three teeth and suffered a fractured nose and black eyes in the attack.
The court heard she had been left with “difficulty eating” and was “self-conscious”.
Imposing an 18-month jail sentence suspended for two years, Judge Christopher Cornwall said: “I have reminded myself by looking at the photographs what a miserable condition she was left in at the end of what was meant to be an enjoyable evening out.
“A dreadful, dreadful mess she was in. She faces the prospect of further surgery.
“Why did that happen? It happened because Heidi Rowland behaved disgracefully, she went to the venue already drunk and misbehaved.
“The evidence suggests you were sitting quietly before the relevant incident. You were putting your coat on with the intention of escorting her off the premises.
“You did involve yourself, believing she was in some sort of peril, but the way you went about it could scarcely have been more misconceived, just simply striking out blows with your fist to her face at a time when her freedom of movement was restricted.”
He ordered him to pay £2,000 compensation to victim at £300 a month and £1,000 costs
Jamie Hamilton, defending, said: “Mr Curran was not the catalyst for the events that happened that night.
“In no way was the violence he used premeditated, it was all in the heat of the moment.”