In what was an open game at the Ataturk Stadium in Istanbul on Tuesday night, the Wales international recieved his first dismissal in club football for two bookable offences, which could leave Arsene Wenger with a selection headache.
Alex Oxlade-Chamberlain thought he had won it for 10-man Arsenal with a late run and strike at goal, but Besiktas 'keeper Tolga Zengin brilliantly tipped the ball onto the post.
Former Chelsea hitman Demba Ba was the most threatening for the home side, even hitting the crossbar straight from kick-off at the start of the match.
The result should stand Wenger's men in good stead for the second-leg, but a lack of cutting edge will be worrying to fans.
Ba’s incredible effort in the first few seconds caught us all by surprise, and with Wojciech Szczesny beaten, the woodwork came to the Pole’s rescue.
It set the tone for an impressive start for the Turks. Ba brought the best out of Szczesny with a well-timed volley as they pressed for an early strike.
Down the other end, Olivier Giroud could not connect with a low Alexis Sanchez cross, and Santi Cazorla fired wide after working space for the shot well.
Ba then had the best chance of the half, turning Laurent Koscielny inside out, but fired wide with Szczesny beaten.
Straight away, Giroud had another chance in behind, but he elected to try and flick the ball over Zengin, but again he failed to get any purchase on the ball.
After the interval, the pace of the game slowed, and the play became scrappy as the uneven pitch started to frustrate both sides.
Besiktas created another good opening at the start of the second half, as Olcay Sahan cut in from the left only to curl his effort wide of the far post having done all of the hard work.
Giroud again stuck with the theme of not connecting with low crosses, but this time, he really should have got on the end of a drilled pass from the impressive Sanchez.
Ramsey was then given his marching orders for cynically tugging the shirt of former Arsenal trainee Oguzhan Ozyakup. Needless, and could be costly in the long run.
Oxlade-Chamberlain’s late chance came and went, and a winner would have been undeserved on the balance of play, but the slatemate still leaves the Gunners firmly in the driving seat, even if their forwardline looks anything but clinical.
The return leg at the Emirates is live on Sky Sports 5 HD next Wednesday, with coverage underway from 7pm.