"I think the book was 100 percent hearsay, at least all the stuff I read and the quotes that I read, which was a little bit disappointing", said Williams, who played in her first Grand Slam since giving birth a year ago.
Sharapova was on the brink when she netted a forehand off balance to go 4-1 down and the two-time French Open champion then netted a backhand to crash out.
Sharapova's autobiography - the 31-year-old said her rivalry with Williams started after 2004 Wimbledon, where Sharapova won her first Grand Slam by defeating Williams in straight sets. Some of those matches were very defining for me.
A sweeping, running forehand into an open court gave her the set with Muguruza having managed just two winners.
Muguruza improved in the early stages of the second set, holding serve for the first time and backing it up with a break on her way to a 3-1 lead.
Against Kerber, Halep stumbled out of the gate, dropping the first set in a tiebreaker.
(3) Garbine Muguruza bt. She was helped by her opponent as the Russian produced three double-faults in the opening game to gift it to the Venezuelan.
Sharapova did not play a point in the fourth round, because Serena Williams pulled out of their much-anticipated showdown with an injured chest muscle.
The Romanian's mentality has often been questioned, but she showed her mental strength and remains on course to win her first Grand Slam.
Nadal lost the opener 6-4 against 11th-seeded Diego Schwartzman but began to play better after a rain delay of just under an hour.
But it was the German who started the stronger, out-hitting her rival with lethal accuracy, to win the first four games as Halep struggled to find her serving rhythm and peppered the tramlines with unforced errors. Sharapova was the French Open champion in 2012 and 2014; Muguruza took the trophy in 2016.
(1) Simona Halep bt. Halep saved two match points to win that one.