Cenk Tosun denied Monaco a much-needed lifeline in their bid to avoid early elimination from the Champions League as he salvaged a 1-1 draw for Group G leaders Besiktas.
Ligue 1 winners Monaco, who reached a continental semi-final against Juventus last term, had just one point from their previous three pool matches when arriving at Vodafone Park in Istanbul.
Rony Lopes' opener at the end of the first half put them briefly above RB Leipzig and Porto in second place but prolific Black Eagles striker Tosun would soon find a leveller from the penalty spot to reapply the brakes.
Besiktas, the reigning Turkish champions who have stormed to three straight wins in Europe this season, threatened first with former Manchester United winger Zoran Tosic heading against Jemerson to win a corner.
At the other end Youri Tielemans had his headed effort repelled by Fabricio in the Besiktas goal.
Monaco lost key midfielder Thomas Lemar to a shoulder injury in the 26th minute, allowing Stevan Jovetic to enter the fray, and it was not long before the Montenegrin set up Lopes for a promising attempt that was saved.
Lopes - once of Manchester City - did not have to wait much longer to get on the scoresheet as, in stoppage time, he rifled home from 18 metres.
Monaco were therefore in high spirits heading inside for the half-time break but their joy was short-lived.
Jorge's foul on Ricardo Quaresma in the 53rd minute drew a red card and earned Besiktas a penalty, which Tosun - the author of a brace in October's reverse fixture - stuck beyond the outstretched glove of Danijel Subasic.
Shortly after the restart, Ryan Babel burst through the Monaco defence to set up Quaresma, who blasted wide of a gaping goalmouth.
Les Rouges et Blancs regrouped and with quarter of an hour to go carved out a double opportunity. Andrea Raggi's header at a corner was pushed onto a post before fellow defender Kamil Glik scooped the loose ball over the bar.
As time ticked away Monaco looked the side most likely to grab a winner, with Keita Balde firing just wide before Guido Carrillo nodded Joao Moutinho's free-kick into Fabricio's hands.
Monaco successfully defended against a last-gasp Besiktas raid as Moutinho threw himself in front of a Quaresma shot, but the difference between dropping two points or all three was negligible for the frustrated principality team.