Kristiyan Balov and Atanas Iliev scored in the first half as Bulgaria avenged their opening-match defeat to Luxembourg and moved firmly back into contention in League C Group 4.
Balov breaks the deadlock
Luxembourg started positively and created an early opportunity through Vincent Thill, but Bulgaria gradually grew into the contest.
The visitors took the lead in the 19th minute when Kristiyan Balov combined with Emil Tsenov before cutting inside and firing a low effort into the bottom corner beyond Luxembourg goalkeeper Anthony Moris.
Bulgaria continued to threaten, with Martin Minchev coming close to extending the advantage before Moris intervened.
Iliev doubles Bulgaria's advantage
Bulgaria's pressure produced a second goal in the 34th minute.
Georgi Rusev delivered a dangerous cross from the left into the Luxembourg penalty area, where Atanas Iliev met the ball first time and fired past Moris to make it 2-0.
The visitors took their two-goal advantage into half-time, leaving Luxembourg facing a difficult second half.
Luxembourg push for a comeback
Luxembourg responded with greater attacking intent after the interval.
Omar Natami came close to reducing the deficit after being found by Vincent Thill, but Bulgaria goalkeeper Daniel Naumov produced an important save.
The hosts continued to create openings, with Mathias Olesen and Aiman Dardari both testing Naumov from distance.
Despite sustained pressure, Luxembourg could not find a way through the Bulgarian defence.
Bulgaria hold on for important victory
Bulgaria remained dangerous on the counter-attack and managed the closing stages effectively.
Naumov made another important save in the 89th minute, denying Olesen after a free-kick had created an opening inside the penalty area.
The final whistle confirmed a 2-0 victory for Bulgaria.
Luxembourg 0-2 Bulgaria
• Bulgaria: Kristiyan Balov 19', Atanas Iliev 34'
• Luxembourg: No goals
Luxembourg slide to bottom of Group C4
The defeat leaves Luxembourg bottom of Group C4 after four matches.
Jeff Strasser's side had started the campaign impressively with a 2-1 away victory over Bulgaria in Plovdiv, but subsequent defeats against Iceland, Estonia and now Bulgaria have dramatically changed their position.
Following Estonia's 0-0 draw with Iceland on the same night, Iceland lead the group with eight points, while Luxembourg sit at the bottom.
Bulgaria avenge opening-day defeat
For Bulgaria, the victory was particularly significant because Luxembourg had beaten them 2-1 in Plovdiv in the opening round of the competition.
Balov's opener and Iliev's first-half strike gave Bulgaria the clinical edge they lacked in that first meeting.
The result also keeps Bulgaria's campaign alive as the Nations League group heads towards its final two matchdays.
Luxembourg face crucial November fixtures
Luxembourg will now have to regroup before their final two Group C4 fixtures in November.
They will host Estonia on 13 November before travelling to face Iceland on 16 November.
With the team currently bottom of the group, both matches will be crucial if Luxembourg are to avoid finishing the Nations League campaign in last place.