In the opening period it appeared as if Bayern might wrap up the tie there and then as Toni Kroos and Thomas Muller gave them an early two-goal advantage over a shell-shocked Arsenal side. To Arsenal’s credit, they made a contest of it after the break and, with the crowd in full voice, it appeared as if a rousing comeback may be on the cards when Lukas Podolski capitalized on a Manuel Neuer error to head home.
But Mandzukic’s somewhat fortunate late goal took the sting out of the encounter and surely all-but secures Bayern’s place in the quarterfinals. It was a fitting result after an astute and occasionally spectacular performance from a Bayern side that could certainly claim to currently be playing the best soccer in Europe.
Coming into the match on the back of heavy criticism for a shock FA Cup defeat to Blackburn, it was essential that Arsenal got a foothold early in the contest. But Bayern were never about to let that happen and and Arsenal’s hopes of progressing took a massive dent just seven minutes into the first-leg. The opportunity came from very little as Muller was given too much space down the right but produced a poor cross in to the edge of the box. But with Aaron Ramsey merely hanging out a leg to try and intercept and the rest of the Arsenal midfield failing to track back, coupled with Per Mertesacker not getting out quickly enough, Kroos was able to strike a shot with exemplary technique that flew past Wojciech Szczesny and into the net.
It was the last thing Arsenal’s fragile state needed and the effects were clear for all to see. Bayern quickly settled into their possession game, while they’re incessant work off the ball prevented Arsenal could struggled to hold the ball let alone make any attacking inroads.
There was a heavy sense of inevitability when Bayern’s second goal arrived after just 21 minutes. Again Arsenal can take a large slice of culpability as Daniel van Buyten was allowed to run unchecked to the near post and meet a corner from the right. The Belgian’s header was only barely kept out by Szczesny, but, with Podolski looking on, Muller pounced and stretched to volley the rebound into the roof of the net.
Arsenal were unable to muster an effort in anger until past the half-hour mark when Mertesacker’s powerful effort from the edge of the box was blocked by Van Buyten. It was a moment that contrasted sharply with the non-closing down of Kroos for Bayern’s opener and encapsulated one of the many differences between the sides.
Arsenal began to show some signs of life toward the end of the period and Walcott, unable to make any impact in a central striking role, should have done better after a ball inside the box from Bacary Sagna.
Yet, by half-time Bayern were perhaps left wondering how the score line was not more emphatic. Certainly Mandzukic should have done better than heading inches wide from Philipp Lahm’s cross right before the interval.
Whatever was said at half-time seemed to have the desired effect as Arsenal came out on the front foot and playing like their Champions League fate and perhaps their season and maybe more was on the line.
The home side's early impetus got the crowd engaged and 10 minutes into the second half they reduced their arrears.
From Jack Wilshere’s corner from right, Neuer came but didn’t get anywhere near the cross and with his defenders vacating the danger zone, the ball ran through to Podolski who had the simplest of tasks to head into an unguarded net from six yards out.
While Bayern weren't near as dominant as in the opening 45 minutes, they still showed plenty going forward and Javi Martinez might have done better with a header over with Szczesny stranded.
Sensing Arsenal needed one final push to try and give his side a chance in the second leg, Wenger brought both Tomas Roisicky and Olivier Giroud off the bench with 20 minutes remaining.
The two substitutes had an instant impact as Rosicky curled a deep ball over to the right for Walcott, who fired in a near-post cross and Giroud with his first touch met the ball cleanly on the volley but it soared straight into the unmoved Neuer and bounced to safety.
With that went Arsenal's last chance to take some comfort from the home leg as almost immediately Bayern further emphasized their advantage.
Bayern substitute Arjen Robben fed Lahm down the right of the box and Mandzukic just got to the low cross ahead of Sagna at the back post and the ball took a kind loop up in the air over Szczesny and into the net.
The goal sucked the life out of the majority inside the Emirates and Bayern settled once again into comfortable possession with Arsenal unable to come close to reducing their arrears before the final whistle was greeted by more boos from an increasingly disgruntled home support.