A man who shamelessly snatched a souvenir cap from Kamil Majchrzak intended for a young boy has been ridiculed online for his ‘trashy’ behavior.

The incident unfolded Thursday afternoon on Court 11, shortly after Polish tennis star Majchrzak pulled off the biggest win of his career – a thrilling five-set upset over No. 9 seed Karen Khachanov. 

But in ugly scenes that quickly went viral, a man standing next to the boy reached out, grabbed the cap and stuffed it into his bag – leaving the youngster looking crestfallen and asking ‘what are you doing?’ as Majchrzak walked away, unaware of what had just happened.

‘Stealing from a child is completely disgusting,’ one Reddit user wrote. 

Another added: ‘What a total piece of sh**. I’m glad it was caught on camera. Hope he enjoys his 15 minutes of fame.’

‘When I see a grown up man behaving like this it truly makes me sad. How does a person needs to be to act like this, what are they thinking when they are inside their head? Crazy…’ wrote another.

Another chimed in writing, ‘This guy should be banned from all tennis tournaments, disney and all chuck-e-cheeses. Who does that.’ 

Kamil Majchrzak was signing tried to give his cap to a young boy, but a man snatched it away

The disappointed young boy was seen asking ‘what are you doing?’ after the man took the cap

Dozens of other viewers labeled the man a ‘jerk,’ ‘terrible,’ and ‘selfish,’ while one post sarcastically declared him the ‘winner of the douchebag of the year award.’

However, Majchrzak moved to put things right on Friday, taking to Instagram to appeal for help in finding the boy. 

After the match I didn’t record that my cap didn’t get to the boy,’ he wrote. ‘Thanks to @asicstennis I’ve got enough caps, so I’m prepared for that. Hey guys, could you help me find the kid from my match. If it’s you (or your parents see this), please send me a DM.’

Just hours later, the Polish star confirmed the boy had been located. Sharing the same pictures of the incident on his story, he added: ‘I am impressed by the power of the internet. We got it! All good now.’ 

The heart-warming resolution capped a dramatic 24 hours for Majchrzak, whose on-court exploits have already made headlines in New York.

On Thursday he produced a performance of extraordinary grit to topple Khachanov 2-6, 6-7(4), 6-4, 7-5, 7-6(5) in four and a half hours – saving five match points along the way.

It marked his first win over a Top 10 opponent and matched his best-ever run at the US Open, where he is now into the third round.

Khachanov, who had beaten Majchrzak at Wimbledon in July, appeared in full control after taking the first two sets, breaking twice in the opener and edging a tight second in a tiebreak.

But the Pole refused to fold, taking the third set as errors crept into his opponent’s game.

The clip has since sparked fury online, with fans branding the unidentified man a ‘scumbag’ and ‘trashy’

The selfish man then stashed the cap in his bag before the player realised what was happening

Majchrzak issued a plea for his followers to help him identify the boy – and it quickly worked

He held firm again in the fourth before breaking late to force a decider, and even when Khachanov opened a 5-3 lead and served for the match, Majchrzak dug deep to fend off three match points and break back.

Two more slipped away for Khachanov in the next game as Majchrzak again refused to yield, ultimately forcing a deciding tiebreak.

There he raced into an early lead and, despite brief resistance from the Russian, held his nerve to complete a famous comeback 10-5.

‘This is the biggest win of my career,’ Majchrzak said afterwards. ‘It shows I can compete with the very best and gives me so much belief.’

His reward is a third-round meeting with Swiss qualifier Leandro Riedi, ranked 435 in the world but also coming off a giant-killing win after upsetting No 19 seed Francisco Cerundolo.

Victory would see Majchrzak reach the last 16 of a Grand Slam for the first time.