Valenciennes and Reims go into their clash tomorrow knowing that the winner will be virtually assured of Ligue 1 football next season.
Both sides are six points clear of the relegation zone going into the weekend and with only five matches of the season remaining after this round, a win would all but secure safety.
VA also have to face Nancy, who currently occupy the final relegation place, next week and manager Daniel Sanchez is glad that his side have their destiny in their own hands.
``The next 10 days are crucial,'' he said. ``We consider Reims and Nancy two of the teams similar to us.
``We know we must be careful against Reims. We must defend well but we also seek to attack and create the danger. We don't want to play the game all in our own half.
``It was said at the beginning of the week that we will need commitment, investment and determination.
``The game against Reims will be played as if it is vital. We must consider this game as a Cup match. This is a decisive match and the result will influence a lot.
``The winner will be very happy and will have made a big step towards safety.''
Reims defender Mohamed Fofana echoed Sanchez's thoughts but insisted his team will maintain their commitment until the end of the season.
``This is obviously a very important game,'' he said. ``If we win Sunday, we won't be mathematically safe but I think we will have taken a big step towards our goal.
``We cannot relax mentally, especially not now. We have never been as close to safety.''
He added: ``At present the situation is more exciting than stressful.
``It will also depend on other results.''