Second half goals from Paraguayan Junior Alonso, Nicolas de Preville and Dutch-Moroccan Anwar El Ghazi earned Bielsa a winning return to France two years after walking out of Marseille following the opening game of the 2015/16 season.
For Ranieiri it was his first match back in Ligue 1 since leaving Monaco despite leading them to a second placed finish behind Paris Saint-Germain in 2014.
Lille, champions of France in 2011, dominated throughout but proved ineffective in front of goal during the first period.
But that all changed after the break and from the moment Alonso opened the scoring three minutes into the second period with a crisp shot from outside the area, Lille never looked back.
De Preville doubled the advantage midway through the half from the penalty spot after Nicolas Pallois felled Kevin Malcuit in the box.
El-Ghazi put the game to bed just three minutes later, converting a cross from Rominigue Kouame before making an emotional tribute to stricken Dutch compatriot Abdelhak Nouri, who suffered brain damage after collapsing during a pre-season friendly for Ajax.
The victory moved Lille up to second behind Lyon, 4-0 winners over newly-promoted Strasbourg on Saturday, in the early table.
PSG unveiled world record signing Neymar before their 2-0 win over Amiens at their Parc des Princes home on Saturday in a festive atmosphere.
Champions Monaco got the season underway on Friday night with a come-from-behind 3-2 win over Toulouse.
Giants Marseille close out the weekend's action at home to minnows Dijon later on Sunday.