Adrian Mutu again struck a late winner for the Viola and Prandelli said: "Fiorentina's last five results read like Scudetto form with four wins and a draw.
"The performances, however, say anything but. We have been very fortunate, but above all our games have been decided by champions. We could have come away with much, much less against Lazio, Genoa and Chievo.
"It's great in terms of results, but sooner or later our luck will run out and that is when we need the real Fiorentina back. The race for fourth is still long and increasingly tight."