The former Leicester City manager's team well beaten on opening weekend of the new football season in France.
Tough start to Ligue 1 for Ranieri as Nantes trounced by Bielsa's Lille
Marcelo Bielsa inflicted a punishing blow on Claudio Ranieri in the battle of big-name coaches as Lille opened their Ligue 1 campaign with a 3-0 win over Nantes on Sunday.
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.
"We played with a lot of dynamism, our tempo was very, very high, we made very few mistakes and our goalkeeper was pivotal," said Argentine Bielsa, 62.
"We've been working together for two months and we were desperate to play the first official match.
"It's far too early to make conclusions about our game, whether that's the positives or the negatives."
Ranieri was appointed Nantes coach in June, four months after his sacking by Leicester City, the club he guided to a fairytale Premier League title in 2015/2016.
This was the Italian's first game in Ligue 1 after he left Monaco in 2014, despite leading them to a second-placed finish behind Paris Saint-Germain.
"I wasn't surprised by Lille's performance, they're a very good team with some very good young players," said the 65-year-old.
"I think they will have an important say in the title race. They were more motivated than us and that's no good.
"I want my players to be more motivated. We can lose but we cannot lack motivation or aggression."