Leicester face Atletico Madrid at the Vicente Calderon Stadium in their Champions League quarter-final first leg on Wednesday.
The Spanish side are third in LaLiga and favourites to knock the Foxes out of Europe in the last eight.
Here, we take a closer look at Diego Simeone's Rojiblancos.
Atletico have lost just three times in their last 25 matches in all competitions - twice to Barcelona - and sit third in LaLiga.
Saturday's 1-1 draw at Real, thanks to Antoine Griezmann's late equaliser, left them 10 points behind their city rivals in the title race.
While Simeone's men are unlikely to win the league for the first time since 2014 they have lost just four times at home, twice in LaLiga, this campaign.
They have also only failed to score twice in their last 25 games - the 0-0 draw against Bayer Leverkusen which set up their clash against Leicester and a 3-0 defeat at Villarreal in December.
The in-form France striker has scored seven times in his last nine games for club and country and is the hosts' biggest threat with 25 goals so far this term.
He is averaging a goal every 171 minutes in LaLiga - behind Lionel Messi's strike rate of a goal every 83 minutes but still an impressive figure.
The forward has been consistently linked with Manchester United and Chelsea this season and boss Simeone is laughing off the speculation.
After Griezmann scored in Saturday's 1-1 draw at the Bernabeu Simeone was asked if he thought it was a shame the 25-year-old was leaving. He reportedly smiled and said: "Well I don't know where he is going."
Simeone - known to many for his altercation with David Beckham at the 1998 World Cup - has been boss at the Vicente Calderon since 2011.
He won LaLiga in 2014 - the first time the club were champions since Simeone won it with them as a player in 1996 - to break Real and Barcelona's stranglehold on the crown.
Simeone also clinched the Europa League in 2012 and guided the Rojiblancos to the Champions League final in 2014 and 2016 - when they twice lost to Real.
The former Inter Milan midfielder has already warned his team to be wary of Leicester, saying: "This is a team that was able to win the English league. We know that the game will be very tough against a rival that is similar to us."
While Leicester are in their debut season in the Champions League and stepping into the unknown Atletico have plenty of experience.
Last season's beaten finalists - losing on penalties to Real Madrid - are three times runners-up and have made the final twice in the last three seasons.
They are yet to win the Champions League but did claim the Europa League five years ago, beating Athletic Bilbao, to follow up their maiden Europa League title in 2010.
Atletico have also won the Super Cup twice and the Cup Winners' Cup in 1962.