A viral clip of an Atletico Madrid U12 captain lashing out at a Real Madrid player during a pre-match handshake has left fans stunned - as they joked 'Diego Simeone's influence runs right the way through'.

Footage of the incident has circulated on social media after the local youth side derby but fans were taken aback by the attitude of the Atletico player who appeared aggressive while greeting an opposition player before the game.

As the first player to walk through to shake the hands of the rival Real Madrid players, the captain of the Atletico side is seen angrily slapping the hand of one individual before turning to him and lashing out again.

The player on the receiving end refuses to react, and instead continues shaking the hands of the Atletico players - who, unlike the captain, embrace their opponents in a friendly manner.

Fans later descended on X to express their shock at the incident, with some condemning the player for his attitude.

One said: Simeone's influence [runs] right the way through,' referencing the tenacious and aggressive nature Atletico boss Simeone has instilled in his senior squad since joining in 2011.

Another was far from impressed, writing: 'El capitan setting a terrible example. How old are they? Would of subbed him straight away.' 

A third post claimed he looked like future skipper of the third team, while one called his behaviour 'embarrassing'. 

The Atletico youth side went on to win the game 2-1. 

Atletico Madrid and Real Madrid teams have been no stranger to aggression and heated moments in the first team.

The last game between the pair - a 3-1 win for Atletico in September - saw 23 fouls and four yellow cards.

The game prior to that was a 3-1 win for Madrid which saw a total of 29 fouls, six yellows and one red card for Atletico.