Day 5 of the US Open ended up being quite a topsy turvy one for the seeded players with Roberta Vinci (28), Alize Cornet (22), Andrea Petkovic (18), Ernst Gulbis (11) and Fabio Fognini (15) all falling by the way side.

South African Kevin Anderson was involved in yet another battle, this time with Jerzy Janowicz of Poland. Janowicz took the first set tiebreaker but Anderson then stepped up to the plate and won the next three sets. The final score was 6-7 6-2 6-1 6-3.

It was however the Ladies who provided the action on Day 5.

Second seeded Romanian Simona Halep suffered a shock defeat at the hands of 32 year old Croatian Mirjana Lucic-Baroni 7-6 6-2, Lucic-Baroni who was a former teenage progidy and who has been absent from the tennis circuit for a number of years due to various reasons, overpowered Halep with her forehand and ended the match by serving an ace. She deservedly received a standing ovation from the Grandstand crowd.

The tiny Italian Sara Errani (13) was up against the former two time champion and crowd favourite, American Venus Williams (19). The players had met three times before with Williams reigning victorious each time. In what turned out to be a roller coaster two hour match, Errani took the first set 6-0. Williams then turned the match around by taking the second set 6-0. The third set went to a tie breaker and it was Errani who just managed to edge past the former champion, taking the set and match 7-6 (7-5).

In another upset, Swiss teenager Belinda Bencic, in her first US Open appearance, ousted the sixth seeded German Angelique Kerber 6-1 7-5.

Roger Federer, Maria Sharapova, Jelena Jankovic, Tomas Berdych, Grigor Dimitrov and Caroline Wozniacki all kept their title hopes alive by advancing to the second week.