Djokovic advances, Serena to face Venus in US Open quarters

World No.1 Novak Djokovic reached his ninth consecutive US Open quarter-finals, while women's top seed Serena Williams defeated 19th seeded Madison Keys 6-3, 6-3 to set up a last eight clash against her older sister Venus.

Serbian tennis star Djokovic on Sunday beat Spain's Roberto Bautista Agut, seeded 23rd, 6-3, 4-6, 6-4, 6-3. The 28-year-old will now play another Spanish opponent, the 28th seeded Feliciano Lopez who beat Italy's Fabio Fognini, Efe reported.

The 32nd seeded Italian had earlier been responsible for a major upset in the third round when he came back from two sets down to send Rafael Nadal packing from the tournament.

Djokovic, who dropped his first set of the tournament, required just over three hours to take his overall record against Bautista to 3-0.

Nine-time Major winner Djokovic fired eight aces, committing only two double faults, and converted seven of the 14 break point opportunities. He hit 42 winners but also committed 37 unforced errors to Bautista's 34 and 28 respectively.

Frenchman Jo-Wilfried Tsonga beat compatriot Benoit Paire 6-4, 6-3, 6-4 to reach the quarter-finals, as did defending champion Marin Cilic, who battled past Jeremy Chardy 6-3, 2-6, 7-6 (2), 6-1.

In the women's singles category, world No.1 Serena took just 68 minutes to crush the 20-year-old Keys, while Venus, 35, triumphed 6-2, 6-1 in her earlier match -- albeit in even less time, 52 minutes -- against Estonia's 19-year-old Anett Kontaveit.

The Estonian served well, as did Serena, but wracked up 19 unforced errors to six for her rival, including six double-faults, with most of them at unlucky points in the match.

Serena has won the past four major tennis tournaments, including the US Open last year and is trying to become the first player to win all four Grand Slam titles in one season since Steffi Graf accomplished the feat in 1988.

The duel between the Williams sisters will be their 27th meeting on the court, with Serena holding the lead in past encounters 15-11, including her victory over Venus at Wimbledon.

Kristina Mladenovic beat Ekaterina Makarova 7-6 (2), 4-6, 6-1, while Italian Roberta Vinci got a walkover from an unfit Eugenie Bouchard.