Battling it out to meet either Fenerbahce or Olympiacos next month, the two clubs are split by one goal ahead of their second-leg clash, after Villa won 2-1 on home turf.
Match preview
In a game that saw several shifts in momentum, Lille fell behind to an early Ollie Watkins header at Villa Park, before the hosts' captain John McGinn steered home a well-placed effort shortly after half time.
A late reply from Bafode Diakite at least reduced Les Dogues' deficit, after Aston Villa goalkeeper Emi Martinez played a major role in keeping the visitors at bay by making several saves, and they were perhaps unfortunate not to leave on level terms.
Paulo Fonseca's side had gone unbeaten through 10 previous Conference League matches this season, qualifying included, but that setback leaves them staring at an exit from the club's first quarter-final tie in a major European competition.
Ligue 1 winners as recently as 2021, Lille also made the Champions League's last 16 only two years ago, but reaching the semis of UEFA's third-tier tournament would break further new ground for a team well-placed to dine at Europe's top table next season.
Only an inability to turn draws into wins has stopped them topping the 'best of the rest' rankings behind French league leaders Paris Saint-Germain; though they sit fourth in Ligue 1, LOSC are just four points from second place - and with one game in hand following a weekend off from domestic duty.
In addition to winning four of five home fixtures in their Conference League campaign, Lille are also 15 games unbeaten at Stade Pierre-Mauroy; however, they have yet to progress from a two-legged European tie after losing the first leg.
Set for their first competitive game in France since a 1-1 draw in Lille 22 years ago - when the clubs met in UEFA's now-forgotten Intertoto Cup - Aston Villa have come a long way since losing their first Conference League group fixture back in September.
Having since progressed as Group E winners, the Birmingham club are now within touching distance of next month's final, after going eight subsequent games unbeaten, of which they have won six.
Taking part in their fifth European quarter-final - but a first since 1997 - Villa were crowned champions of Europe by beating Bayern Munich in 1982, but more recently they had become accustomed to mediocrity.
The arrival of current boss Unai Emery - who lifted the Europa League trophy for three successive seasons as head coach of Sevilla, then once more with Villarreal - has transformed their fortunes, and having won his last seven quarter-finals in continental competition, he will expect to get the job done again on Thursday.
Another eye-catching result in the Premier League last week restored the Villans' status as slight favourites to take England's fourth - and as things stand, final - Champions League place for next season, as they downed title-chasing Arsenal in the capital.
Top scorer Watkins was on target again in an impressive 2-0 win, but Villa still face a tough run-in and will take nothing for granted in their top-four tussle with Tottenham Hotspur just yet.
Should they now avoid defeat in Lille, Emery's side will equal the club's longest unbeaten streak in Europe - which dates back to when they won that lone European Cup - and more importantly seal a spot in the Conference League semi-finals.
Lille Europa Conference League form:
D
W
W
W
D
L
Lille form (all competitions):
D
D
D
W
W
L
Aston Villa Europa Conference League form:
W
W
D
D
W
W
Aston Villa form (all competitions):
D
W
L
D
W
W
Team News
Lille have benefited from a weekend off, so should be fully firing for Thursday's contest, in which Jonathan David will spearhead the hosts' front line.
As at Villa Park, the Canada striker could be supported by in-form winger Edon Zhegrova, while England Under-21s star Angel Gomes is in contention to start after overcoming a hamstring injury to make a brief cameo appearance in Birmingham.
Paulo Fonseca can also choose from Remy Cabella, Adam Ounas and Hakon Arnar Haraldsson in the final third, but fellow forwards Andrej Ilic and Tiago Morais are still sidelined by injury.
Meanwhile, Aston Villa defender Clement Lenglet makes the trip to his homeland after missing the first leg with a knock, and Matty Cash returned to the squad last weekend, having been ruled out for several weeks by an injury sustained on international duty. However, the visitors will still be without long-term absentees Boubacar Kamara, Emi Buendia, Tyrone Mings and Jacob Ramsey.
Douglas Luiz is set to return in midfield, as he will be suspended again for Sunday's league game at home to Bournemouth, while Leon Bailey - who opened the scoring against Arsenal - could be promoted from the bench.
Starting up front, star striker Ollie Watkins has scored in four of his last five Europa Conference League appearances and sits third in the Premier League's Golden Boot race on 19 goals.
Lille possible starting lineup:
Chevalier; Santos, Diakite, Yoro, Ismaily; Andre, Bentaleb; Zhegrova, Cabella, Gudmundsson; David
Aston Villa possible starting lineup:
Martinez; Konsa, Carlos, Torres, Digne; Luiz, Tielemans; Bailey, McGinn, Rogers; Watkins
We say: Lille 2-2 Aston Villa (Aston Villa win 4-3 on aggregate)
As evidenced by an absorbing first leg, these sides are well-matched, and Lille's hopes of turning things around are certainly helped by hosting Thursday's return.