Ana Ivanovic and Victoria Azarenka still had to play their fourth round match-up that had been cancelled the previous day, and the two former world No. 1s put on quite a show first up on Arthur Ashe Stadium on Tuesday.
The Serbian 13th-seed Ivanovic was able to get the early advantage hitting 17 winners to Azarenka's four in the first set, but the Belarusian hit back in the second with Ivanovic hitting five double-faults and 15 unforced errors.
That forced the match into a deciding third set and despite Azarenka serving four double-faults, she was able to break Ivanovic's serve four times and take out the match 4-6, 6-3, 6-4 to book in a quarter-final match-up with unseeded Slovak Daniela Hantuchova.
It was then onto the women's quarter finals action and world No. 1 Serena Williams made the most emphatic statement possible that she is the woman to beat in New York once again with a 6-0, 6-0 slaughter of Spain's 18th-seed Carla Suarez Navarro in just 52 minutes.
Williams hit four aces, broke Suarez Navarro's serve six times on only seven opportunities and hit 20 winners while allowing the Spanish veteran to only win a total of 18 points for the entire match.
Williams is searching for her 17th Grand Slam title and fifth win at the US Open, and has now not dropped a set on her way to the semi finals with straight-sets wins over Suarez Navarro, Sloane Stephens, Yaroslava Shvedova, Galina Voskoboeva and Francesca Schiavone.
The 31-year-old will now face China's Li Na in the semi finals after the fifth-seed beat Russia's Ekaterina Makarova in three tough sets on Tuesday, 6-4, 7-6 (5), 6-2 in two hours and 20 minutes.
While it is going to be a massive ask for Li to overcome Williams in the semi finals, if she does she will be a real chance of winning the second Grand Slam title of her career after previously winning Roland Garros in 2011.
Li will have to turn around her head-to-head record against Williams, though, with the American having won eight of the nine meetings with Li's only win coming in 2008 at Stuttgart.
Williams has won all three Grand Slam meeting with Li at the 2006 Australian Open, 2010 Australian Open and 2010 Wimbledon.
The other women's quarter finals will now take place on Wednesday starting with the battle of two Italian veterans – the unseeded Flavia Pennetta and Roberta Vinci.
Then next up in the evening sees the clash between Hantuchova and Azarenka.