It was at Manchester United where Cristiano Ronaldo cemented his status as one of the world’s best footballers.The Portuguese legend famously impressed against the Red Devils in a pre-season friendly while playing for his first club, Sporting Lisbon, in the summer of 2003.After roasting John O’Shea, United’s players pleaded with Sir Alex Ferguson to sign the talented young Ronaldo during the flight back to Manchester.Several weeks later, Ronaldo completed a £12.24 million move to Old Trafford and the rest, as they say, is history.After a promising but inconsistent first three seasons with United, Ronaldo transformed into a world-beater after the 2006 World Cup finals.He was unstoppable during his final three years with the Premier League giants and became United’s first Ballon d’Or winner since George Best in 1968 after landing his hands on the prestigious individual accolade in 2008.After promising to give Ferguson and United one more season following the 2008 Champions League triumph, Ronaldo eventually completed a dream £80 million move to Real Madrid in 2009.While Cristiano has netted many extraordinary goals for both Madrid and Juventus since then, arguably the best goal of his illustrious career was scored in a United shirt.His stunning long-range pile-driver away at FC Porto will always be remembered as one of the best goals in Champions League history and deservedly so.

Cristiano Ronaldo's greatest ever assist?

No doubt you’ve all seen that goal hundreds of times since he scored it - but what about Ronaldo’s best ever assist?

Well, it’s quite possible that he produced his greatest assist in a United shirt, too.

During a Premier League clash against Aston Villa at Old Trafford, the Portuguese superstar set up Wayne Rooney with a remarkable no-look back-heel.

Watch the footage here…

Ronaldinho would have been proud of that assist!

The ball rolled perfectly into the path of Rooney, who rounded Scott Carson before sticking the ball in the net.

Football's most underrated assist?

Why is this assist not shown more often? It’s incredible - assuming he meant it, of course!

It’s certainly a strong contender for the most underrated assist ever.

This was one of 34 Premier League assists that Ronaldo registered during his six-year spell in Manchester.

He also bagged 84 goals in 196 games, sealed the 2007-08 Golden Boot award after netting 31 goals in 34 appearances, and was named the league’s Player of the Season in 2006-07 and 2007-08.