Chelsea midfielder Michael Ballack believes that his side's 2-1 defeat to Fenerbahce in Istanbul can be overturned in London.

He told UEFA.com, "We saw that against Olympiacos as well, south Europeans are very fanatical supporters.

"It's the way they follow their team, it's fantastic for them. But we have a good stadium with a nice atmosphere too."

The German believes that his team are more than capable of clawing back an aggregate advantage over the Turkish outfit.

"We are every strong at home, we have a good record at home but we have to concentrate over 90 minutes," Ballack warned.

"Our first leg defeat? It was important we scored but when you see the game we should have won it. We are disappointed but we have a good chance in the second leg.

"It was a strange game. I played well, we fought well, we controlled the game, we went 1-0 up, and it looked like we would win.

"But sometimes you do not concentrate for one second and it changes the game. That happened. It is disappointing at the moment but we have to look forward and we have everything in our own hands."