Sergio Aguero has warned his former Manchester City teammates not to get complacent as they set out to defend their Champions League semi-final lead over Real Madrid tonight.

The Premier League leaders are 4-3 up on aggregate ahead of the clash at the Bernabeu, but the ex-striker believes Real's successful comebacks against both Paris Saint-Germain and Chelsea earlier in the competition should serve as a warning to City.

“Pep Guardiola should be happy with his team in the first match against Real Madrid because they played some amazing football and scored some really good goals, if the team is playing well and scoring you need to make sure you're in control of the game and then you have a good chance of winning," said Stake.com global representative Aguero.

“Three goals for Real Madrid is not perfect for Manchester City, but they are ahead and away goals do not change things anymore.

“Real Madrid have already beaten PSG and Chelsea to get here in the Champions League, and they are two of the best teams - the Champions League winner from last year and the best team in France with Lionel Messi and so many stars.

“City know this and have to have 100 per cent focus on the match and not think they have won until the final whistle because Real Madrid fight until the end, they will want to win and City can't think the job is done."