New York - Angelique Kerber reached the US Open quarter-finals on Sunday which
left Serena Williams needing to reach the final to have a chance of
retaining the world number one spot.
Kerber defeated Petra Kvitova
6-3, 7-5 to pile the pressure back on to the American who is looking to
break Steffi Graf's record of 186 weeks as the world number one.
If Kerber reaches the final, then Williams must win the title top stay on top of the pile.
"When I was a kid, of course I was dreaming of winning Slams and being one day No. 1, and now it can happen," said Kerber.
"But I'm trying to not put pressure on myself, because I know I have to win a few more matches to reach the No 1.
"When it happens it will be an amazing feeling, because that was also one of my dreams when I was a kid."
Kerber will face Italy's Roberta Vinci for a spot in the semi-finals.
Results from the seventh day of the 2016 US Open tennis championships at Flushing Meadows on Sunday (x denotes seeded player):
Novak Djokovic (SRB x1) bt Kyle Edmund (GBR) 6-2, 6-1, 6-4
Jo-Wilfried Tsonga (FRA x9) bt Jack Sock (USA x26) 6-3, 6-3, 6-7 (7/9), 6-2
Lucas Pouille (FRA x24) bt Rafael Nadal (ESP x4) 6-1, 2-6, 6-4, 3-6, 7-6 (8/6)
Gael Monfils (FRA x10) bt Marcos Baghdatis (CYP) 6-3, 6-2, 6-3
Caroline Wozniacki (DEN) bt Madison Keys (USA x8) 6-3, 6-4
Anastasija Sevastova (LAT) bt Johanna Konta (GBR x13) 6-4, 7-5
Roberta Vinci (ITA x7) bt Lesia Tsurenko (UKR) 7-6 (7/5), 6-2
Angelique Kerber (GER x2) bt Petra Kvitova (CZE x14) 6-3, 7-5