Martin O'Neill's inspired substitutions saw Celtic come from behind to breathe life into their Europa League campaign with a much-needed 3-2 home victory over Besiktas.
Junior Olaitan's goal - a rebound after Sam Johnstone saved his penalty - looked like condemning Celtic to a fifth consecutive European defeat for the first time in the club's history.
But the introduction of Callum Osmand, Camilo Duran and Colby Donovan just after the hour was a masterstroke from O'Neill.
Osmand fired in the equaliser with his first touch before setting up Duran to round the goalkeeper and put the Hoops ahead.
With five minutes left, Celtic suffered a major blow as Orkun Kokcu came on for Besiktas to fire into the bottom corner from 25 yards.
But Duran was not done. He picked up the ball from Kieran Tierney and poked it into the net two minutes later to restore the Hoops' lead.
Celtic remain in the bottom 12 of the Europa League table, but, with four games left, they still have a chance of reaching the knockout stages.
Remember, remember the fifth of November? It is a night the Celtic fans are unlikely to forget.
Key moments from Celtic Park...
8: CHANCE! Some brilliant play from Celtic, all starting from Sebastian Tounekti. He eventually crosses the ball into the box for Benjamin Nygren, who sends it wide.
11: BLOCK! Cameron Carter-Vickers recovers to stop Leandro Trossard from getting a shot away for the visitors.
26: CHANCE! Kasper Hogh is waiting in the box for Tounekti's cross, but it is diverted out for a corner.
50: SAVE! James Forrest with the first shot on target! He picks the ball up out wide and drives into the box. He fires low towards Alexander Nubel, who gets down to save.
52: PENALTY TO BESIKTAS! Jordan Lotomba lunges in for a needless challenge on Ernest Poku, and the referee points to the spot.
54: GOAL BESIKTAS! Johnstone pushes Olaitan's spot-kick back out, but he taps in the rebound.
59: CHANCE! Lotomba runs all the way from his own half to the Besiktas box but cannot get a shot away.
65: GOAL CELTIC! Osmand makes an immediate impact, firing into the net with his first touch.
67: SAVE! Liam Scales' deflected header is pushed over the bar by Nubel.
79: GOAL CELTIC! Duran collects the pass from Osmand, rounds the 'keeper and fires Celtic in front.
85: GOAL BESIKTAS! Kokcu takes aim from around 25 yards and his strike finds the bottom corner.
87: GOAL CELTIC! Duran picks up the ball from Tierney, takes his time and pokes the ball into the net. The hosts are back in front.