Enraged Manny Pacquiao fans are targeting his opponent, Jeff Horn, on social media after their hero lost his title fight.

Not even his wife, Joanna, was spared with Pacquiao supporters attacking her with vicious sexist comments.

At the time of publishing, Horn's latest Facebook post had more than 6,800 comments - most of them abusive - with thousands more on other photos.

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Angry internet trolls attacked Aussie boxer Jeff Horn (pictured) on social media after his win

Horn's social media accounts have been flooded with harsh insults from Pacquiao fans

On Instagram one fan wrote: 'F*** you jeff horn ur a cheater and australians are cheaters [sic]', and another called him a 'tryhard b****.'

Facebook was also littered with comments such as 'dirty f***ing fighter... boooooo' and 'special child horn!! Booooo!'

Mean-spirited trolls even attacked Horn's wife Joanna, writing vile sexist remarks on photographs of the high school sweethearts.

Horn (pictured being interviewed immediately after the match) won by unanimous decision

Jeff Horn (pictured, right) and his wife Jo Horn (pictured, left) are expecting their first child

Disgusting comments could be found all over photos of Jeff and Joanna Horn on Instagram

Nasty Manny Pacquiao fans even left death threats on Instagram - 'Hope your wife die'

'Weak. Fatty wife motherf***er,' wrote one user.

'Maybe buy her a treadmill on her next birthday,' said another.

Some comments were more sinister, with users threatening to kill Horn for 'cheating' and 'paying off the judges'.

'Hope your wife dies,' one sick user commented.

Horn won against defending boxing world champion Pacquiao in a unanimous decision at Brisbane’s Suncorp Stadium on Sunday.

After the massive upset win, underdog Horn became WBO welterweight champion.

Horn won against defending boxing world champion Pacquiao in a unanimous decision at Brisbane’s Suncorp Stadium on Sunday

Pacquiao was a firm favourite to win the match, with bookmakers offering five to one for Horn to come out on top

The 29-year-old former school teacher revealed his wife Joanna was pregnant in a ringside interview after the fight.

'This is not the best moment of my life, that moment is yet to come with my beautiful wife Joanna, she's pregnant and having our first child,' the emotional boxer said.

'Thanks for your love and support.'

The champ also had a few choice words for Pacquiao's arch rival Floyd Mayweather, waving a cane and saying: 'Floyd, come have a real fight.'

Pacquiao was gracious in defeat, saying that he accepted the judges' decision.

'He was very tough. It's okay. Part of the game,' said the Filipino superstar.

Pacquiao was gracious in defeat, saying that he accepted the judges' decision

After the massive upset win, underdog Horn became WBO welterweight champion

A Filipino man gestures while watching the fight, which ended in controversy after Horn was unanimously declared the WBO welterweight champion

It was the fight that enthralled the nation, but not everybody was happy with the result.

Controversial boxing legend Anthony Mundine declared Horn had ‘manifested his dream into reality’, and Sports Sunday presenter Emma Freedman called Horn’s performance ‘extraordinary’.

But ESPN personality Stephen A Smith called Horn's win 'highway robbery' in his analysis following the fight.

Others still labelled the victory a 'joke' and called the fight 'rigged.'

ESPN commentator Teddy Atlas was inconsolable after the decision, saying the scorers didn't follow the rules.

'They gave a trophy to the local kid for trying hard, you're not supposed to get it for trying hard, you're supposed to get it for winning!' an exacerbated Atlas shouted.

Atlas then began his post-fight interview with Horn by saying 'I thought you lost,' as Pacquiao smiled and laughed nearby.

American athletes, including NBA and NFL stars, were also critical of the result.

Controversial boxing legend Anthony Mundine said Horn was an inspiration to Australian boxing in a delighted Facebook post

Green Bay Packers quarterback Aaron Rodgers said 'boxing is a joke'. He was joined by countless U.S. NBA and NFL stars