Piti, who scored 18 goals for Rayo Vallecano last term, missed the last two games through injury but he climbed off the bench in the 78th minute on Sunday before curling home a stoppage-time winner from 25 yards out.
That helped Granada follow in the footsteps of Barcelona and Real Madrid as the only clubs to have beaten Levante this season and denied their opponents the chance to move level with fourth-placed Villarreal on 20 points.
It might have been a different story though if Levante striker Nabil El Zhar had netted his first-half penalty instead of seeing it saved by Roberto Fernandez.
Roberto also produced a number of other vital saves while his opposite number Keylor Navas was similarly impressive as their heroics looked set to see the game finish goalless.
That was until Piti's late intervention though, as Granada climbed out of the bottom six with their fourth win of the campaign.
The game exploded into life in the 23rd minute when the Granada goal suddenly came under concerted pressure, sparked by a spilled cross from Roberto.
The visiting keeper helped make amends for that mistake with a brilliant block from Papakouli Diop's thunderbolt, but Granada failed to properly clear the danger and Levante attacked again and won a spot-kick when Manuel Iturra was adjudged to have tripped El Zhar inside the area.
The Morocco international could not capitalise from the spot though as his effort was parried by Roberto diving to his right.
That seemed to spark the visitors into life and Navas was called into action to save from Jose Recio and Diego Buonanotte, the second a fine diving stop.
Buonanotte then raced from inside his own half before lashing a left-footed shot just wide as the teams went into the interval still looking for the first goal.
The floodlights went off during half-time to plunge the stadium into darkness, and led to the second half being delayed by quarter-of-an-hour.
When the match resumed it was the two goalkeepers back in the spotlight with Roberto saving from Andreas Ivanschitz and El Zhar before Issam El Adoua saw a looping overhead kick land on top of the crossbar.
Navas then produced the save of the match, and one of the saves of the season, as he somehow managed to turn Youssef El Arabi's powerful close-range header over the bar one-handed.
That stunning stop ultimately proved to be in vain though as the Costa Rica international, despite getting a hand to the ball, was unable to keep out Piti's stoppage-time free-kick as Granada took the points.