Lyon have been one of the stories of the 2014-15 Ligue 1 season so far with Fournier's youthful side having moved to the top of the table ahead of Marseille and PSG a month ago.
With the likes of 23-year-old striker Alexandre Lacazette, 25-year-old captain Maxime Gonalons and 20-year-old midfielder Corentin Tolisso leading the way, Lyon have a one-point lead and a game in hand on second-placed Marseille ahead of their trip to Lorient on Sunday.
PSG will host Caen on Saturday, two points adrift of Lyon.
Fournier is wary of PSG, who held Lyon to a 1-1 draw last week and seem to be finding form after a scratchy first half of the campaign.
"Honestly, the way they've been playing in the last three or four weeks, they're starting to look a lot like the PSG of last season," Fournier told The Ligue 1 Show.
"They're maybe still a bit inconsistent in some games but they've got a certain amount of room to move that we don't possess.
"The title should really be PSG's when you consider the money they've invested and the quality of their squad.
"Now we're not sulking about the fact we're top of the league. It wasn't easy for us at the start but we've been on an unbelievable run in the last five months, only losing one game, and we deserve to be where we are."
Lyon have dropped points in their past two matches with draws against Monaco and PSG but Fournier denies his team's intensity has dropped.
"No, I don't think we're tired," Fournier said.
"Our opponents have been studying the way we play and they're setting themselves up in a very solid way against us.
"Also maybe now that we're top - and this is the most troubling aspect - maybe the players are feeling pressure and that's shown in certain games."
Fournier admitted Lyon's consistent winning form has exceeded his expectations, considering how young his squad is and that they have missed the likes of Clement Grenier and Yoann Gourcuff to long-term injuries.
"It's quite unexpected because we're starting a new cycle, the club has introduced a policy that focuses on academy players," the 47-year-old coach said.
