When athletes (accidentally) attack

Sport is competitive and sometimes, when things are not going your way, frustration can get the better of you.

That's what happened to 17-year-old Canadian tennis player Denis Shapovalov, who cost his team their Davis Cup tie with Great Britain after he was disqualified in the deciding match.

Britain's Kyle Edmund had just broken serve to lead 6-3 6-4 2-1 when frustration got the better of Shapovalov, who fired a spare ball angrily towards the crowd - but instead he hit the ball straight into the umpire's eye.

Ouch.

A default followed, giving Britain a 3-2 victory in the World Group first-round tie.

Shapovalov said he was "incredibly ashamed and embarrassed" and the umpire, Arnaud Gabas had to be taken to hospital to be checked over.

However, Shapovalov is not the first athlete to accidentally hurt someone in the thick of the action...

LeBron James

Court-side seats have pros and and cons.

Pros: you get close to the action. Cons: you get close the action.

Here, golfer Jason Day and his wife Ellie get cleared out by basketball legend LeBron James.

LeBron is 6ft 6in tall and 113kg, so having him flying into you must be pretty brutal.

Ellie Day was stretchered out and taken to hospital with a concussion, but made a full recovery.

David Nalbandian

Another unbelievable moment from the world of tennis as Argentina’s David Nalbandian loses it in the final at Queen's in 2012.

A mighty, frustration-induced swing of Nalbandian’s foot propelled a small advertising board into the shin of a line judge.

Looks painful - and the line judge proceeded to make his displeasure pretty apparent.

Nalbandian forfeited the match, handing his opponent Marin Cilic the title.

Badou Jack

Middleweight boxers Badou Jack and James DeGale were trading punches in their unification fight in January when the referee got a bit too close to the action.

As the bell rang to end the fifth round, referee Arthur Mercante Jr stepped in to break things up. As he did, Jack planted a left hook on Mercante, who stumbled and had to be held up.

He shook it off, and the fight ended eventually in a draw. With a chin like that, our money is on Mercante for the rematch.

Tim Henman

Back in 1995, a young Tim Henman and his doubles partner Jeremy Bates became the first players to be disqualified from Wimbledon in the Open era, all because Henman lost his rag.

They were leading opponents Jeff Tarango and Henrik Holm, so things were going well for the British pair - but then Henman was undone by a net cord.

As a ball girl ran across to her next position, Henman swung in frustration at another ball he was holding, hitting it at full-force flush into the side of the ball girl’s head.

Henman and Bates were kicked out of the competition, but the nearly man of British tennis would eventually rebuild his reputation at the All England Club enough to have a hill named after him.

Kirk Cousins

Here's Washington Redskins quarterback Kirk Cousins running to pick up a first down against the Carolina Panthers.

As Cousins gets pushed out of bounds, he starts sliding and takes out a nearby cheerleader.

The poor girl has nowhere to go and face-plants the floor.

Luckily that pom-pom helps to absorb most of the force.

This boxer

It’s hard not to feel for the referee here, as he tries to separate the pair and ends up catching a left hook instead.

And one guy who does it all on purpose... Zlatan Ibrahimovic

Manchester United striker and taekwondo enthusiast Zlatan Ibrahimovic loves to kick things.

Often the result is a goal for his team, but sometimes the outcome can be painful for his team-mates.

Just ask his former AC Milan colleague Antonio Cassano.

Cassano is just one of many players to have felt the force of Ibra's high kicks over the years.

Cheeky Zlatan.