Nadal got the ball rolling against Fognini with an early break, and the Spaniard didn’t look back as he sealed the opening set in 31 minutes.
The 31-year-old secured an immediate break in the second set to leave his Italian opponent with a mountain to climb, and two further breaks followed as Nadal wrapped up the match after one hour and two minutes on court.
Meanwhile, Roger Federer made light work of Ukrainian Alexandr Dolgopolov, winning 6-4 6-2 to advance to the last eight.
The 36-year-old broke the world number 41 in the first game before saving a break point in the tenth to seal the opening set 6-4.
Federer cranked up the gears in the second set, breaking Dolgopolov twice to seal victory after exactly an hour on court.
The 19-time Grand Slam champions faces either Richard Gasquet in the next round after he overcame fellow Frenchman Gilles Simon 7-5 6-7(5) 6-3.