Friday 20 February 2015 15:31, UK
Taiwan's Yen-Hsun Lu upset top seed Kevin Anderson of South Africa 7-6 (8-6) 6-3 on Wednesday night in the second round of the Delray Beach Open.
Lu, 31, has an ATP ranking of 61 and his win sets him up for a quarter-final match against fifth seed Adrian Mannarino of France, a 6-2 6-2 winner over Denis Kudla.
Anderson's loss, together with second-seeded John Isner's loss to Marinko Matosevic on Tuesday, is the first time the top two seeds have left the tournament before the quarter-finals since 2006.
Showing it is a hotbed for upsets, the top seed departures also means it will be the 22nd time in the tournament's 23-year history that the top seed does not win the tournament. Mardy Fish in 2009 was the only No 1 to capture the title.
Fourth-seeded Ivo Karlovic of Croatia also advanced, outlasting 18-year-old Thanasi Kokkinakis of Australia 7-6 (7-4) 7-6 (7-2).
Karlovic, who turns 36 at the end of the month, will face seventh-seeded Steve Johnson in the last eight.
Johnson east past 17-year-old wild-card Andrey Rublev of Russia 6-3 6-3.
