Seventh-seeded Ana Ivanovic has always been a wildly inconsistent player at the majors, and today’s loss did not improve her reputation. She unluckily drew 2014 Australian Open finalist Dominika Cibulkova, who has struggled with injuries lately, but displayed resurgent form today. She took out the Serb, 6-3, 3-6, 6-3.

Ivanovic’s quarter of the draw has been blown wide open due to her loss and the last-minute withdrawal of third seed Maria Sharapova. The highest seed left in that quarter is 13th seed Ekaterina Makarova, who reached the semifinals in Flushing Meadows last year.

Last year’s runner up and fourth seed Kei Nishikori crashed out to Frenchman Benoit Paire, after having match points in the fourth set tiebreak. The underachieving 41st-ranked player in the world produced brilliant play to win just his fourth Grand Slam match this year, 6-4, 3-6, 4-6, 7-6(6), 6-4. Nishikori dumps out of the tournament after being handed an easy draw this year.

Last year’s surprise champion Marin Cilic failed to display championship form in his match against Argentine Guido Pella, but still managed to pull through in straight sets, 6-3, 7-6(3), 7-6(3). Cilic advances to become the favorite in his quarter, with fourth seed Nishikori out of the tournament.

Number one seed and 2011 champion Novak Djokovic dismantled Brazilian Joao Souza in 73 minutes, 6-1, 6-1, 6-1. The Serb did not face a single break point and appeared to be in dominant form as the oddsmakers’ favorite.

American veteran and fan favorite Mardy Fish began his retirement campaign with a win over Italian Marco Cecchinato, 6-7(5), 6-3, 6-1, 6-3 on Grandstand. The 33-year old plans on ending his career at his home major tournament after a 15-year run on tour.

Coco Vandeweghe defeated Sloane Stephens in an all-American battle on Louis Armstrong, 6-4, 6-3. The Wimbledon quarterfinalist advances to face another American, Bethanie Mattek-Sands.

Last year’s quarterfinalist and showman Gael Monfils retired with a back injury in his match against Ukrainian Illya Marchenko. Monfils fails to back up his incredible showing from last year, when he was up two sets to love and held two match points against five-time champion Roger Federer in their quarterfinal match.

Serena Williams spent exactly half an hour on court before her opponent Vitalia Diatchenko retired with an Achilles injury down 0-6, 0-2. Williams lost just five points in the opening match to her now infamous Calendar Year Grand Slam campaign.

Many doubted two-time champion Rafael Nadal’s chances this tournament due to his tough draw and inconsistent year. However, he emphatically took down 18-year-old Borna Coric, 6-3, 6-2, 4-6, 6-4. The legendary Spaniard avenged his loss from the Swiss Indoors last year, when he was suffering from appendicitis. He advances to face Diego Schwartzman next.