Lille lead Ligue 1 and have sauntered into the Cup final despite having a smaller squad than the likes of PSG and being the pick of only the shrewdest and most risk-taking gamblers at the start of the campaign.
Their charge towards a possible second double, having first achieved the feat in 1946, has stunned even the club president who thought this term would be one of consolidation before moving into a new stadium next year.
Instead, the 'Mastiffs' have hounded opponents into submission and snarled their way through matches with a dash of pedigree talent like winger Eden Hazard also making the difference.
Tuesday's 2-1 win at tricky customers St Etienne made their first league title since 1954 look increasingly likely and Cup final success on a rare visit to the Stade de France could do them a power of good for the championship run-in.
"This is the best preparation for Saturday's final," coach Rudi Garcia told reporters after the midweek victory.
"The cup final is a real event for our club and we fully intend to win."
PSG, who beat Monaco after extra-time to triumph in last year's showpiece, have had an up and down season in comparison to Lille but victory on Saturday would go some way to appeasing their success-hungry fans.
Tuesday's 2-2 home draw with third-bottom AS Nancy in Ligue 1 summed up their problems, decent in attack but occasionally weak in defence.
Parisians hope their players will respond when Ligue 1 is replaced with the ticker tape and media attention of a final.
"This French Cup means a lot to us. We hold it dear, we will try everything to keep hold of it," said PSG forward Guillaume Hoarau.
"When you are a player and you find yourself in a final it's very important."
PSG are fourth in the league and could even make the third Champions League qualifying berth.
Whatever happens in the final the Europa League place that could have been available for winning the Cup will almost certainly go to the sixth-placed Ligue 1 club instead.
