US Open 2015: Stars continue to shine, Johanna Konta springs a surprise

Roger Federer, Andy Murray, Stan Wawrinka made it to the quarter-finals on the sixth day of 2015 US Open. (Source: AP)

Roger Federer played with ease and managed to get past Philipp Kohlschreiber in 6-3 6-4 6-4. (Source: AP)

Another Swiss, Stan Wawrinka advanced after beating Ruben Bemelmans 6–3, 7–6(5), 6–4 to pre-quarters on Saturday. (Source: AP)

Stan Wawrinka is scheduled to take on American Donald Young whom he had faced in 2011 US Open and lost. (Source: AP)

Britain's Andy Murray also reached the round of 16 with a clinical 6-3 6-2 7-5 victory against Brazilian Thomaz Bellucci. (Source: AP)

Andy Murray will next face 15th-seeded South African Kevin Anderson, who defeated Austrian Dominic Thiem in straight sets. (Source: AP)

In women's singles, Simona Halep of Romania had her task cut out and she delivered with an easy 6–2, 6–3 win over Shelby Rogers of United States. (Source: AP)

Simona Halep played some fabulous tennis as she made just nine unforced errors in the match. (Source: AP)

Victoria Azarenka of Belarus, seeded 20th, defeated 11th seed Angelique Kerber of Germany 7-5, 2-6, 6-4. (Source: AP)

Britain's Johanna Konta, was the surprise of the day, as she defeated 18th seed Andrea Petkovic 7-6(2) 6-3 to reach the fourth round of a Grand Slam for the first time in her career. (Source: AP)