Arsene Wenger's future was plunged into further doubt on Wednesday as Thiago Alcantara inspired Bayern Munich to a 5-1 rout of hapless Arsenal to leave the Gunners facing a seventh straight Champions League last-16 exit. In a highly lop-sided encounter, Bayern had little difficulty in netting the goals as Arsenal looked hapless in front of the German side. On the other hand, defending champions Real Madrid too stepped closer to booking a place in the last-8 of the tournament with a 3-1 win over Serie A outfit Napoli at home.
Bayern extended their Champions League record to 16 straight home wins by flooring the Gunners with three goals in ten second-half minutes.
"That was a good performance, which perhaps wasn't so expected," said Thiago, who scored twice.
"We were playing at home, knew we had to score a few goals and everything worked very well after the break."
Bayern knocked Arsenal out at the same stage in 2005, 2013 and 2014 and look comfortably placed to make it four times after romping through Wednesday's first leg.
The Allianz Arena defeat raises the pressure on Wenger for the return leg on March 7 with only Alexis Sanchez's away goal for comfort.
The result matched the 5-1 group-stage thrashing Arsenal received in Munich in November 2015 -- the club's joint record away defeat in Europe.
Arjen Robben's superb curling shot gave Bayern the lead on 11 minutes, but Sanchez levelled by drilling home after Manuel Neuer saved his penalty on 30 minutes.
Robben also admitted he was surprised by the big win.
"Things worked very well," said the Dutch winger.
"I am a bit surprised that we played so well, but on the other hand, I know the team has great character and can move up a gear when it matters."
Bayern hit top gear after the break with a flurry of goals in quick succession.
Robert Lewandowski headed Bayern back into the lead on 53 minutes before Thiago added two in quick succession while Thomas Mueller came off the bench to complete the rout.
Real Madrid bounce back vs Napoli
Real Madrid shrugged off conceding an early away goal to take a huge step towards a seventh straight Champions League quarter-final as goals from Karim Benzema, Toni Kroos and Casemiro sealed a 3-1 win over Napoli on Wednesday.
Lorenzo Insigne's stunning 40-yard strike had the travelling hordes in dream land after just eight minutes of the last 16 first leg.
However, Benzema soon headed home an equaliser before Kroos and Casemiro fired home from outside the box early in the second half to give the holders a commanding lead ahead of the second leg on March 7.
We played a great game, above all at the start," said Madrid boss Zinedine Zidane.
"The shame was to concede given the start we made, but we equalised quickly to get back in the game and in the end it is a logical result."
Napoli coach Maurizio Sarri lamented his side's slackness in possession, but believes they still have a chance back at the San Paolo given it had taken what he considered Real's best performance in three months to beat them.
"Clearly Madrid played their best game of the past three months and we didn't play our best," said Sarri.
"If we manage to play at our best we are not that far away. We may lose (in the second leg) but we can go for it."
With former Napoli great Diego Maradona watching on, the atmosphere reached fever pitch before kick-off as up to 10,000 travelling fans were estimated to have made the trip from Naples for only their side's second ever appearance in the last 16.