An in-form Lille side started stronger as Olivier Giroud skewed Ayyoub Bouaddi’s cutback wide from a promising position, before Benjamin Andre was off target with two further efforts.
The visitors’ superiority was vanquished on the half-hour, though, when Bouaddi was sent off for bringing down Alan Virginius in the box, resulting in a penalty.
However, Young Boys could not capitalise, as Chris Bedia missed his first spot-kick this season at the fourth attempt, with Berke Ozer making a brilliant double save having also denied Virginius on the rebound.
Bedia tried to amend for his miss immediately in the second half, but he curled just wide from a narrow angle.
It was not long after that Young Boys found the breakthrough, as Darian Males sneaked the ball in at the near post after Virginius’ deflected cross found him on the hour mark.
Lille did not offer much going forward after being reduced to 10 men, with Giroud forcing Marvin Keller’s only save of the game with a precise strike heading towards the bottom corner.
In the end, Young Boys ended a nine-match winless streak against French teams in UEFA competition as they earned a place back in the top 24 of the league phase table, despite having a man sent off themselves late on as Tanguy Zoukrou picked up two quick bookings.
Lille’s away woes continue with this a fourth loss in their last five trips in all competitions; their hopes of finishing in the top eight are now in major doubt.
Flashscore Man of the Match: Alan Virginius (Young Boys)