Slovak defender Lubomir Guldan opened the scoring after 33 minutes, Bulgaria international Ivan Stoyanov made it 2-0, converting a penalty just before the interval, and Mihail Alexandrov completed the rout five minutes from time.
Montana defender Milen Lahchev received a straight red card for improper conduct on the stroke of half-time.
Ludogorets, who were in the Balkan country's third division two and a half years ago, earned the honorary title of winter champions after collecting 38 points from 15 games.
The Eagles are based in Razgrad, a town with a population of less than 35,000, but clinched a maiden league title and domestic treble last season.
Levski Sofia are second with 37 points after a 3-1 win at city rivals Slavia in an all-tempered game that featured nine yellow cards and a sending off with both teams struggling to adapt to difficult conditions and the hard pitch.
Levski's Portuguese striker Joao Silva, who came on as a first-half substitute, scored twice soon after the break while Slavia's Yanko Sandanski received two yellows within two minutes midway through the second half.
Litex, coached by former Bulgaria great Hristo Stoichkov, moved up to third with 29 points after a laboured 1-0 win over 10-man Chernomorets Burgas. CSKA Sofia, who face city rivals Lokomotiv on Sunday, are fourth on 28.