Nadal sets up Djokovic clash at Paris Olympics
The winner of 14 French Open titles at Roland-Garros, Nadal prevailed once more on Court Philippe-Chatrier, outlasting his Hungarian opponent 6-1 4-6 6-4.
The Spaniard quickly settled into his stride and wrapped up the opening set in just 31 minutes.
However, Fucsovics responded well with an early break in the second and, though Nadal cancelled it out in game nine, the Hungarian broke again to level.
Nadal appeared in trouble at 2-1 and 40-0 down on serve in the decider, but managed to dig deep and just about hold.
He then gained the crucial break in the following game, before holding out to set up that mouth-watering showdown with Djokovic.
Data Debrief: Nadal and Djokovic set for 'one last dance'
Nadal's victory means a record-extending 60th meeting - and what will likely be the last - meeting with Djokovic.
Once again, they will do battle at Roland-Garros, two years after the Spaniard prevailed in their French Open quarter-final meeting in four sets on his way to a 14th crown.
Nadal demonstrated his quality under pressure once more against Fucsovics, converting four of his eight break-point opportunities, compared to just two of 10 from his opponent.