US Open 2017: Maria Sharapova, Garbine Muguruza exit; Americans Sam Querrey, Venus Williams march ahead

Maria Sharapova, who was back on the grand-slam stage after returning from a doping ban, was knocked out in the fourth round as she lost 7-5, 4-6, 2-6 to Anastasija Sevastova. The 30-year-old Russian finished with 51 unforced errors, compared to 14 for Sevastova. Earlier in the tournament, Sharapova had defeated second seed Simona Halep of Romania in three sets in her first round, creating a huge upset. (Source: Reuters)

Petra Kvitova of Czech Republic also made her way through to the quarterfinals of the US Open after defeating third seed Garbine Muguruza of Spain 7-6, 6-3 in the fourth round of the tournament. (Source: Reuters)

The 17th seed Sam Querrey of the United States also reached the quarterfinals as he pipped Germany's Mischa Zverev 6-2, 6-2, 6-1 in the fourth round of US Open. (Source: AP)

Diego Schwartzman of Argentina defeated Lucas Pouille of France 7-6, 7-5, 2-6, 6-2 in four sets to book his place into the quarterfinal of the US Open. (Source: AP)

With the younger sister Serena Williams blessed with a baby girl, Venus Williams is hoping to lift her 11th Grand Slam title. Venus defeated Carla Suárez Navarro of Spain 6-3, 3-6, 6-1 to reach the quarterfinal of the US Open on Monday. (Source: Reuters)

The 28th seed Kevin Anderson of South Africa registered a four set 6-4, 6-3, 7-6, 6-4 win against Paolo Lorenzi of Italy in the fourth round of the US Open. (Source: Reuters)

Sloane Stephens of the United States celebrates after winning against Julia Georges of Germany by 6-3, 3-6, 6-1 in three sets in the fourth round. Stephens has advanced into the quarterfinals of the US Open. (Source: Reuters)