NEW YORK, Sept 1 (Reuters) - Poland's third seed Agnieszka Radwanska has been bundled out of the U.S. Open by Russia's Ekaterina Makarova in the biggest shock of the women's event at Flushing Meadows.
Makarova struck a barrage of groundstroke winners to topple Radwanska 6-4 6-4 in the fourth round under floodlights on Louis Armstrong Stadium.
Radwanska started brightly, surging to a 4-0 lead, but Makarova peeled off eight straight games to take the first set and lead 2-0 in the second.
Radwanska fought her way back, holding four break points to level the second set at 4-4.
Makarova, the 24th seed, sealed the game with an ace before going on to close out the match in one hour and 32 minutes.
Her next opponent will be China's Li Na after the fifth seed defeated Serbia's Jelena Jankovic 6-3 6-0 on Arthur Ashe Stadium's center court.
The 25-year-old Russian will play her first quarter-final at the U.S. Open after twice reaching the last eight at the Australian Open.
"It feels amazing, I really love this tournament," she said.
Radwanska's loss left her out of the quarter-finals at a major for the first time this year.
(Reporting by Will Swanton; Editing by Ian Ransom)