Tunisia's Ons Jabeur stuns third seed Karolina Pliskova to enter Qatar Total Open quarterfinals.
World no.1 Djokovic will play seventh seed Karen Khachanov on Thursday after the Russian beat Austrian qualifier Dennis Novak.
Czech Republic star Kvitova says she had great battles with Sharapova, who announced her retirement.
The Russian former world number one's ranking is currently 373rd.
The 32-year-old three-time Grand Slam winner has only just returned to training after being out of action since November due to bruising on his pelvic bone.
The stars, who are featuring at the Qatar Total Open 2020, were taken on a private tour of the museum.
Officially opened on November 2017, the Qatar National Library has more than 800,000 books on its shelves and over 500,000 eBooks, periodicals and newspapers, and special collections.
Pliskova, Bencic progressed into the last 16.
Nadal accused Kyrgios of "lacking respect" after he served underarm in their 2019 clash, but the Spaniard said Monday he felt no lingering resentment.
The world number one owns a perfect 14-0 record this season after winning a title for Serbia at the ATP Cup followed by a record-extending eighth Australian Open crown.
Star players including tournament’s top-seeds Ashleigh Barty, Karolina Pliskova, Belinda Bencic, Elina
Svitolina, Sofia Kenin, Kiki Bertens and Petra Kvitova were at the event.
10th seed Petra Martic and 12th seed Marketa Vondrousova also crashed out.
The 31-year-old, who is featuring at the Qatar Total Open, was received on her arrival by HE Ambassador Hans-Udo Muzel, the Ambassador of Germany to Qatar.
The Australian Open quarterfinalist defeated Katerina Siniakova of the Czech Republic in the first round.
Two-time Wimbledon champion Petra Kvitova says that with so many youngsters coming up, no player would be able to dominate the game anymore.