FEAR FACTOR - Celtic fans unveil a tremendous 'tifo' ahead of their huge home tie against Barcelona.
THAT'S WHAT I DO - Mesut Ozil formally introduces himself with a supreme first-time finish to open the scoring for Arsenal.
AN ARMY OUT-GUNNED - Napoli, in their eye-catching camouflage change strips, react to going 2-0 down.
THINGS ARE HEATING UP - Schalke fans create a fiery atmosphere in Basel. But they were soon upstaged...
CAUSING A SCENE - ...Greenpeace protesters abseil into St Jakob-Park, halting play for a bit.
D'OH! - Steaua Bucharest defender Daniel Georgievski puts into his own net at home to Chelsea in comical fashion.
ALL BY MYSELF - The banned Juergen Klopp watches from a box as Borussia Dortmund play Marseille.
WHAT ON EARTH IS THAT? - Andre Ayew's acrobatic efforts do not impress goalscorer Robert Lewandowski at Signal-Iduna Park.
YOU'VE GOT TO BE KIDDING - Axel Witsel, no stranger to producing horror challenges, cannot believe this relatively innocuous challenge in Zenit v Austria Vienna earned him his marching orders.
EMERGING FROM THE WRECKAGE - Diego Godin came out of this almighty scramble for the ball to convert an equaliser for Atletico Madrid against Porto.
WAS THIS A PENALTY? Mario Balotelli caused uproar from the Dutch contingent when he salvaged Milan a stoppage-time point with this foul, converted himself from 12 yards.