Finishing from close range following a second phase of a corner, he helped the team to their first win in the competition this season in their penultimate fixture, and a seventh success on the bounce in all competitions for the Gers.
Head Coach Danny Röhl named seven changes to his side as he shuffled the back once again following cup progression six days ago, as the team looked to continue their positive momentum of late.
The Light Blues looked for a fast start in front of the Ibrox faithful as they seeked a first Europa League success of the season in their second to last outing. There was an early half sight of goal for frontman Youssef Chermiti inside two minutes, but Thelo Aasgaard’s cross from the right was slightly behind the Portugueseman as he turned the effort wide.
Diomande was next to break the line for the Gers in a lively start. A ball over the top from Max Aarons acknowledged the run of the midfielder, but for an intervention from Olivier Verdon who stopped him in his tracks as he tried to take the pass in his path.
Petar Stanic was the first player to have a shot on target for either side with any purpose as both clubs settled their way into proceedings. After a period of possession for the Bulgarian outfit, they worked the ball from the left wing to the midfielder, but his shot goalwards was comfortable for Jack Butland to gather.
The best opening of the contest came on the ninth minute-mark with Chermiti going closest to breaking the deadlock. A deft pass over the top from Nico Raskin picked out the forward, whose half volleyed effort was kept out by Hendrik Bonmann between the Ludogorets posts before Mikey Moore was denied by blocks on the follow up on two separate occasions.
A prolonged period of the contest passed with few things to shout about at either end. Djeidi Gassama was looking a livewire down the Rangers left and the most likely to open the door to a potential opening, whilst the visitors were mainly restricted to counter opportunities.
Ludogorets then went agonisingly close themselves to striking first on the night. After keeping possession down the left, a pass inside was backheeled from Stanic, Caio Vidal came onto it inside the area and looked destined to score, but a smart stop down low from Butland denied the Brazilian.
Stanic then had an opportunity of his own but dragged his shot wide from outside the area, as the Bulgarian visitors were starting to grow into the game themselves after the half-hour mark.
An Aarons delivery almost teed up Diomande but for a Son intervention, but from the following corner, the Ivory Coast midfielder broke the deadlock. A short corner between Jayden Meghoma and Aasgaard saw the former fire it into the area. After some good work from Chermiti in a scrappy situation, it broke for the midfielder to stab at home at the near post with his left foot to put Rangers ahead.
The Light Blues were almost the beneficiary of yet another set piece shortly after the restart. A free kick in a crossing position was sent in by Aasgaard, the ball was met by the head of Raskin, but his effort was held by Bonmann before the Belgian dragged a left footed shot wide in the next attack.
The Gers were looking a threat on the counter themselves as they looked for the goal that would give themselves breathing space in the game. Chermiti brought it forward down the left and cut inside, going alone he looked for the far corner but saw his effort pushed away by the Ludogorets shot stopper.
In the next phase of play the hosts had their best opening since the restart. Moore was slipped in by Raskin after a clever one-two, but the Spurs loanee tried to be clever and looked to dink Bonmann, but the effort was comfortably caught by the goalkeeper.
Rangers somehow didn’t double their lead after a sublime piece of skill from Diomande setup substitute Bojan Miovski. A pass into the midfielder saw him spin away into space in the box, he cut it back for the Macedonian but he hesitated and allowed the covering defender to clear to safety.
Coming off the bench, Findlay Curtis almost made an immediate impact forcing Bonmann into a clever save. He cut in off the right flank and looked to place one into the far corner with his left, but for a stop from the goalkeeper to tip it over the bar.
The Bulgarian side threatened towards the latter stages of the game. Threatening to find a way past Butland, but the Gers hold on to claim a first victory in European competition this season, as they now prepare for the visit of Dundee on their return to league action this Sunday.
RANGERS: Butland, Aarons, Djiga, Fernandez, Meghoma, Raskin, Diomande, Aasgaard, Moore (Miovski, 64), Gassama, Chermiti (Curtis, 73)
SUBS: Kelly, Wright, Tavernier, Rothwell, Antman, Danilo, Adamson, Gentles, Stewart
LUDOGORETS: Bonmann, Nedyalkov, Almeida, Vidal (Ivanov, 90), Stanic, Son (Andersson, 90), Duarte, Verdon, Bile (Machado, 63), Naressi (Chochev, 74), Marcus (Tekpetey, 63)
SUBS: Padt, Hristov, Kaloc, Shishkov, Nachmias, Penev