Nadal looked to be cruising through the 3rd round encounter, winning the first two sets and going up a break in the third.
It's hard to say exactly what happened then, but Fognini rallied to win the next three sets and take the match 3-6, 4-6, 6-4, 6-3, 6-4.
It's the first time in 151 matches that Nadal has lost after winning the first two sets.
This year will also be the first time since 2004 that Nadal hasn't won a Grand Slam tournament. Worse still? He only made two quarter-finals.
Watch Fognini close out the match below.
@AussieVideos pic.twitter.com/LXMmEM5Uer
— Brendan Bradford (@1bbradfo) September 5, 2015The pain was etched on Nadal's face as he walked back up the tunnel - although calling it a walk of shame is a bit much. It was probably the match of the tournament so far.
After a disappointing 2015, what's next for Nadal?