Gerrard sent debutant goalkeeper Milan Borjan the wrong way from the spot in added time to earn a win amid a chaotic and stunning finish to the game.
It appeared that the Bulgarians, in the group stages of the competition for the first time, had stolen a remarkable point when Dani Abalo coolly rounded Simon Mignolet and slotted home just before the 90-minute mark.
But Borjan, only signed on Friday due to the visitors' two main goalkeepers being ruled out, made a critical error when bringing down Javi Manquillo in the area.
And Gerrard made no mistake, adding to Mario Balotelli's 82nd-minute strike - his first for the club - to steal the points in Group B on the night Liverpool returned to this tournament after a five-year exile.
Canada's number one was not tested during the early exchanges, though, as Ludogorets more than held their own.
Borjan passed his first test when showing strong hands to keep out Adam Lallana's deflected effort following good work from Balotelli, but it was the visitors who enjoyed the better of the opening half.
Ludogorets were quick to offer a reminder of their threat, however, with Junior Caicara stinging the hands of Mignolet.
Brendan Rodgers' side were still the more dynamic, although further moments of alarm came when Roman Bezjak narrowly shot over.
The game was suddenly end to end, with Borjan turning Gerrard's powerful header over the crossbar.
Bezjak was then denied by the woodwork following a wonderful ball from Marcelinho.
It proved to be only the first act in the late drama, though, as Abalo then capitalised on a lapse in concentration to level on the stroke of full-time - producing a composed finish after rounding Mignolet.
Yet that error paled in comparison to the dreadful moment from Borjan, who miscontrolled a back-pass and then brought down the marauding Manquillo - allowing Gerrard to once again step up and be the hero on a big European night at Anfield.
