Bundesliga leaders Bayern Munich made Arsenal pay for not taking advantage of a penalty in the eighth minute while Atletico Madrid rode the storm at San Siro and came away with a vital away goal thanks to Diego Costa in the second batch of last-16 encounters.
Goal selects the best imagery from the Wednesday night's fixtures as Diego Simeone and Pep Guardiola saw their teams close in on the quarter-finals.
Champions League icon Clarence Seedorf faced his first game in Europe as head coach of AC Milan
San Siro expects! The seven-time European Cup winners anticipate a strong home performance
To the frustration of the home support, Atletico Madrid goalkeeper Thibaut Courtois keeps Milan at bay
A rare chance for Atleti falls to Diego Costa, but his audacious overhead kick fails to break the deadlock
But the Spaniards' top scorer eventually finds the net with a far-post header seven minutes from time
Deigo Costa roars into celebration after heading home a vital away goal for Atletico Madrid
At the Emirates, Arsenal dominate early but Wojciech Szczesny is forced into a fine save from Toni Kroos
Mesut Ozil is tripped by Jerome Boateng in the box and Arsenal are awarded a penalty
The German midfielder dusts himself off but Manuel Neuer palms away the shot with ease
On 37 minutes Arjen Robben is clattered in the area by a clumsy Wojciech Szczesny challange - penalty!
The Poland goalkeeper is shown a red card by the referee and the Gunners are reduced to 10-men
Bayern Munich full-back David Alaba steps up against Lukasz Fabianski but sees his shot hit the post
Arsenal's resolve is broken on 54 minutes when Toni Kroos bends a shot into the top corner
Two minutes from time, substitute Thomas Muller plants home a firm header from a Philipp Lahm cross
Unused substitute Bastian Schweinsteiger smiles as Bayern take a strong advantage to Germany