NEW YORK, NY, USA - While all of the attention was on the World No.1s playing on Arthur Ashe Stadium, Ekaterina Makarova was pulling off the biggest upset of the tournament on Louis Armstrong Stadium, coming alive midway through the first set and stunning No.3 seed Agnieszka Radwanska.
Radwanska had never lost a set in three previous meetings with Makarova and things looked headed the same way as she stormed out of the blocks to a 4-0 lead. But that's when Makarova came alive - she went on an absolute tear, reeling off eight games in a row to build a 64 20 lead. Radwanska won three games in a row to get things back on serve but Makarova went on her own three game run and, after Radwanska held to make it 64 54, the No.24-seeded Makarova served it out at love, 64 64.
Makarova had 28 winners to 22 unforced errors, Radwanska 18 winners to 27 unforced errors.
"I started well, but I think she was just nervous in the beginning and started to play better and better," Radwanska said. "She was hitting the ball very well, and I didn't do anything to win that first set."
Makarova's win over the World No.4 was her fifth Top 5 win, her first one coming in 2012 (No.4 Petra Kvitova at Eastbourne) and the other three coming earlier this year (No.5 Angelique Kerber at the Australian Open, No.3 Victoria Azarenka at Madrid and No.5 Sara Errani just last week at New Haven).
Next up for Makarova will be No.5 seed Li Na. Li has beaten Makarova in all three of their previous meetings - two of them have gone to three sets, but in those meetings Li won 6-2 in the third set.
The US Open still remains the only Grand Slam where Radwanska hasn't reached the quarterfinals. She is a four-time Australian Open quarterfinalist, a one-time French Open quarterfinalist and has had the most success at Wimbledon - a final in 2012, a semifinal this year and two more quarterfinals.
Radwanska is the fifth Top 8 seed to fall before the quarterfinals, joining No.4 seed Sara Errani, No.6 seed Caroline Wozniacki, No.7 seed Petra Kvitova and No.8 seed Angelique Kerber on the sidelines.