Thursday's draw for the last 16 of the European Champions League threw up a series of mouthwatering ties between a number of the continent's top teams -- including a clash between past winners Real Madrid and Manchester United.

The pairing, which means Cristiano Ronaldo will return to Old Trafford for the first time since leaving United for the Spanish side in 2009, headlined a triol of standout ties after the draw was made at headquarters of European football's governing body UEFA in the Swiss city Nyon.

"Oh yes, Madrid!! What a great couple a games that'll be!! @Cristiano see u soon bro!!," tweeted United's former England captain Rio Ferdinand.

Another Spanish club, four-time champions Barcelona, have been pitched into another heavyweight battle as they take on Italy's AC Milan, whose seven European crowns are second only to the nine boasted by Real.

"We will play against Milan! It will be a great qualifying round!" tweeted Barcelona midfielder Cesc Fabregas.

The draw came on the same day that Barca coach Tito Vilanova was due to have surgery to remove a cancerous tumor.

Elsewhere, beaten 2012 finalists Bayern Munich will take on United's English Premier League rivals Arsenal -- whose striker Lukas Podolski will return to the German club where he struggled to make an impact between 2006 and 2009.

"I think we enter this match as the slight favorites, but we can be making the mistake of underestimating them," Bayern chairman Karl Heinz Rummenigge told UEFA's official website.

"Arsenal have struggled at times in the league over the last few months, which a look upon the standings in the Premier League will tell you. But by no means will this be an easy game for us."

Many experts, including former Manchester United goalkeeper Peter Schmeichel, are tipping Borussia Dortmund for glory this season and the Germans must beat Ukraine's Shakhtar Donetsk if they are to repeat their 1997 success.