ISTANBUL - The second leg of the last 16 UEFA Champions League match between Besiktas and Bayern Munich was in full flow in Istanbul on Wednesday when the referee brought a halt to proceedings due to an unexpected pitch invader.

An overly impassioned Turkish fan carried away by the deafening atmosphere in the Vodafone Park? A naked streaker braving the evening chill? A protester trying to use the big stage to make a point?

No, the surprise guest on the pitch in the clash between the leading Turkish and German sides was none other than a curious cat.

There are thousands of stray cats in Istanbul. They populate back alleys, public buildings, concert halls and restaurants and are accorded considerable respect.

And this feisty feline decided to catch a glimpse of the Champions League.

The cat - clearly a Besiktas fan - scampered onto the pitch and made its way to the Besiktas goal in the 50th minute, with Bayern leading 2-0.

Referee Michael Oliver stopped play as fans erupted in guffaws around the stadium.

The cat then obediently made its way off the pitch after a minute and play resumed. The cat's appearance failed to deter Bayern or bring Besiktas some feline luck.

The German side completed an 8-1 aggregate victory in Istanbul, having effectively clinched the last-16 tie following a 5-0 rout last month in the first leg in Munich, as the German giant cruised into the quarterfinals for the seventh year in a row.

For Bayern coach Jupp Heynckes, who replaced Carlo Ancelotti in October, this was his 11th straight win in the Champions League, which set a new competition record.

"It was a convincing result," said Heynckes. "Besiktas hadn't lost here in the Champions League, so it wasn't easy. "We scored at the right times and it's normal that we dropped off a little - losing some focus after winning 5-0 is just human.

"The only negative today is that we picked up too many yellow cards," he said of defenders Jerome Boateng, Mats Hummels and Rafinha, who all earned bookings.

After Thiago fired home early, an own goal by Besiktas rightback Gokhan Gonul put Bayern ahead 2-0 at the start of the second half.

Trailing 7-0 overall, Besiktas finally came to life, grabbing a consolation goal by Vagner Love.

But Bayern notched its third of the evening when reserve striker Sandro Wagner came off the bench to mark his Champions League debut with his first goal at this level.

"It was a really hectic game," said Bayern captain Thomas Mueller.

"We lost the ball a lot, especially in the second half and we didn't have the structure in our game that we had wanted."

Having resisted the urge to name a weakened team after its first-leg romp, Bayern wasted little time taking the lead against the Turkish champion.

Leading scorer Robert Lewandowski surprisingly started up front, leaving Wagner waiting for his elite European debut until the last 20 minutes.

It was a surprise move by Heynckes, with tough Bundesliga games against RB Leipzig and Borussia Dortmund later this month.

Nevertheless, Lewandowski played until the 67th minute, but failed to add to his 32 goals this season in all competitions.

Agence France - presse