Lyon boss Hubert Fournier said the "hardest bit" is still to come after guiding his side to the top of the Ligue 1 table.
When Marseille and Paris Saint-Germain both faltered at the weekend upon their return to league action, Lyon swept aside Toulouse 3-0 to move a point clear at the top.
It capped a remarkable renaissance of the seven-time French champions, who were just a place above the relegation zone after taking only three points from their first four matches of the season.
"The hardest bit doesn't start now. We have already gone through difficult periods. The best is yet to come," Fournier, 47, told media after seeing his team register a fifth successive league win.
"We have to prove ourselves worthy of first place. It's up to us to not think about it too much, and not lose sight of the fact that if we're top tonight, it's because of the work we have done up till now. If we get carried away a little, we'll slide back down."
After missing out on Champions League football last season under Remi Garde and losing experienced heads such as Bafetimbi Gomis and Jimmy Briand over the summer, Fournier was expected to struggle in his maiden season at the Stade de Gerland.
Instead, after a sluggish start that also saw the club knocked out of the Europa League, Lyon's faith in youth has been richly repaid with the likes of the league's leading scorer, Alexandre Lacazette, one of a number of academy graduates in Fournier's side, taking the French top flight by storm.
Though there appears to be no sign of his young charges relenting, Fournier warned talk of the title was premature.
"It's too far away to think about that. We'll see where we are with five or six games to go. Right now, we're too far away and when we turn around and see teams who have made colossal investments in recent years, it makes us very humble," the ex-Reims coach, whose side are a point clear of Marseille and three ahead of PSG, said.
"We're just continuing on our merry way. We are focused on what we have to do and what we have to ask the players. We have to try to give them the right keys to every game. As we are fortunate enough to have a squad that listens, it's simpler."