Nolan Roux's 79th-minute header snatched all three points at the Stade Lille-Metropole to leave Les Dogues eight clear of fourth-placed Rennes.
However, Garcia said that his sights are set higher than Champions League qualification and revealed that he has not given up hope of retaining the Ligue 1 title.
"It's a good step towards the Champions League and that's good," said Garcia. "There are four finals to play.
"We knew the gap at the top could be cut because of this game against Paris and our trip to Montpellier later in the season. But for now we're focusing only on our difficult game at Nice in midweek."
Lille are seven points adrift of leaders Montpellier HSC with just four games left to play.