A penalty from Sven Kums secured Gent's first-ever win in the Champions League, as they defeated a disappointing Valencia 1-0 at Ghelamco Arena.
The Belgian side kept alive their hopes of qualifying for the knockout stages with a well-deserved victory over their Group H rivals.
Captain Kums was the hero for the hosts, converting a 49th-minute penalty that was awarded after Valencia defender Antonio Barragan had blocked a cross with his arm.
The result means Valencia missed out on the opportunity to join Zenit, who defeated Lyon 2-0, in going through to the knockout stages.
Gent merited their maiden triumph, and the final margin of victory would have been even greater had they not been so wasteful in front of goal.
They did everything but score in an opening half they completely dominated.
Danijel Milicevic saw a looping header from Kenneth Saief's cross hit the right-hand post, strike the back of Valencia goalkeeper Jaume Domenech and then roll along the goal line.
If the hosts were unfortunate on that occasion, they deserved little sympathy when Brecht Dejaegere somehow failed to hit the target after 26 minutes.
Left unmarked, the Gent player had only Domenech to beat from six yards out. However, his downward header ended up bouncing up over the crossbar.
Sloppy in possession and shaky at the back, Valencia failed to even have a shot at goal in the first 45 minutes.
They had to improve as an attacking force once Kums had broken the deadlock from the spot, punishing Barragan for blocking Saief's cross with an outstretched hand.
Yet the surge for an equaliser never really materialised. Coach Nuno summoned Joao Cancelo and Andre Gomes from the bench, yet the substitutes failed to lift the lethargic visitors.
Paco Alcacer's low shot from the left forced Matz Sels into a rare save on what was an otherwise easy night for the Gent goalkeeper.
Despite the defeat, a fourth in their last five away games in all competitions, Valencia still sit second in the table on six points.
They travel next to Zenit, while Gent make the short trip to France to face a Lyon side whose qualification hopes are hanging by a thread.
