They result looked inevitable when Domagoj Vida was sent off very early on, although Müller only put them ahead just before the break.
They pulled away in the second half, with Kingsley Coman, Müller again and Lewandowski, twice, all scoring to make Bayern overwhelming favourites to progress to the last-eight.
Vida red cards leaves Beşiktaş with uphill task
Bayern just about beat VfL Wolfsburg 2-1 on Saturday, however only Sven Ulreich and Javi Martínez remained in the starting line-up as Jupp Heynckes reverted to a much stronger line-up – albeit excluding both Arjan Robben and Franck Ribéry. After a draw with Atiker Konyaspor at the weekend, Beşiktaş saw just three changes to their side: Gökhan Gönül, Tolgay Arslan and Jeremain Lens made way for Adriano, Domagoj Vida and Ricardo Quaresma.
On a snowy night in Munich, Beşiktaş started brightly, looking to be positive at the home of the German champions, yet before too long Bayern were clocking up the chances. Müller had two headed opportunities, whilst Coman had a shot parried by Fabri and Arturo Vidal headed a Joshua Kimmich wide.
As so often on these European occasions though, they were about to get a man advantage. A poor pass back from Atiba Hutchinson left Vida exposed as Lewandowski ran onto the loose ball. He slid in and brought him down and, as the last man, the Romanian referee had to send him off. James Rodríguez chipped the resulting free-kick wide.
Müller eventually gives Bayern the advantage
The Turkish side though sent a quick warning that they were down but not as, as Vagner Love jumped on a misplaced header from Kimmich and ran past both Mats Hummels and Jérôme Boateng, only to put his eventual shot over. Bayern would dominate though, and Fabri made a fabulous one-handed save to deny Hummels scoring with a header.
A Bayern had seemed inevitable by that point, but having not come, Beşiktaş kept Bayern on their toes. On a counter, Quaresma moved central from the right, past Hummels, and went for goal from a tight angle, only for Ulreich to keep his shot out at the near post. Love then did brilliant to resist the attention of Kimmich, nutmegging him, before finding Pepe, whose shot was not far over the bar.
In the end though, Bayern did take the lead before the break. David Alaba and Coman had had the freedom of the left side in the first half, and they combined again with Coman beating Adriano, Alaba then getting a touch on the cross before Müller scored with a trademark toe poke past Fabri. There was a question of offside, but he was just about level with the last defender.
Bayern begin cash in on tiring Black Eagles
Even after the goal Beşiktaş looked plucky, yet after coming out for the second half they failed to get going. Adriano conceded an immediately soft free-kick on the very edge of the box, which Lewandowski struck the post with. A couple of minutes later and after combining with Müller, he placed the ball into space in the centre of the box, with Coman running onto it and sliding the ball in to make it 2-0.
The loss of Vida was really starting to tell for the Black Eagles, with Kimmich and Robben, brought on late in the first half for a concussed Rodríguez, now causing all sorts of problems on Bayern’s right. For the third goal, Robben saw Kimmich overlapping on his right, with his cross then put in by Müller, who stuck his foot out and directed it into the goal, with a deflection off Fabri.
The openings kept on coming for Bayern, with Lewandowski putting a difficult chance wide before a Coman cross was headed over by Müller. A rare bright spot for Beşiktaş saw Talisca having a chance at grabbing a vital away goal, but he slipped as he took it and it went over.
Robert Lewandowski joins the scoring party
The rout grew apace as Bayern added the fourth with just over 10 minutes remaining. Kimmich and Robben combined again, with the latter seeking out Hummels. He went for goal from outside the box, which had Fabri scrambling but he got there. Unfortunately for him, the ball went straight to Lewandowski, who wasn’t going to miss a chance like that to grab his first of the night.
Of course they were not done there. Martínez came up from midfield for a shot, which was diverted wide by Fabri. Müller then had the opportunity to score, but he saw the run of Lewandowski and played a clever pass to him, with the Pole left with an easy tap in to put the ball – and ultimately himself too – in the back of the net.
Whilst the atmosphere in Istanbul for the second leg in three weeks’ time will be intimidating, it is very difficult to image Bayern not progressing to the quarter-finals when the two meet again.