After pulverising Arsenal, Ancelotti says Bayern played 'fantastic' football

'I am a bit surprised by the score, but it is the Bayern mentality.'

'When it matters we are always there.'

Bayern Munich coach Carlo Ancelotti heaped praised on his team after their 5-1 demolition of Arsenal in their Champions League round of 16 first leg on Wednesday following their most dominant performance of the season.

Bayern rode roughshod over Arsenal in the second half, scoring three goals in 10 minutes to take a four-goal cushion into the return leg on March 7.

"We played fantastic football. It was a deserved victory, the balance was there and we were compact and quick. It was a very important result," said Ancelotti, in his first season in charge.

"This result is very important but we still have a game in London where we have to show the same passion," the Italian told reporters.

"But we still will be carrying something good with us to London after this game."

The goal flurry started shortly after Arsenal centre back Laurent Koscielny went off injured early in the second half as Bayern shrugged off recent lacklustre domestic performances.

Ancelotti will also be feeling more comfortable after fans had started grumbling because Bayern's attack was lacking the firepower of past seasons.

"We should score in London but it is a very, very good starting position," said Bayern captain Philipp Lahm, who will miss the return leg through suspension.

"It should be enough for us to go through."

The Bavarians have eliminated Arsenal at this stage of the competition on three previous occasions, including 2013 and 2014, and look likely to do so again.

Thiago Alcantara scored twice and goals from Arjen Robben, Robert Lewandowski and substitute Thomas Mueller completed the rout.

"We started really well," said winger Robben, who put Bayern ahead with a superb 10th-minute strike.

"We felt today we had space to play our game.

"I am a bit surprised but it is the Bayern mentality. When it matters we are always there...despite not having necessarily played well this year so far.

"I don't think we have qualified yet but we would have to lose 4-0 and that is something that should not happen in life," the Dutchman added.