Delray Beach - Taiwan's Lu Yen-Hsun upset South African top seed Kevin Anderson 7-6 (8/6), 6-3 on Wednesday to reach the quarter-finals of the ATP Delray Beach Open.
The 61st-ranked Asian standout dropped only 12 points on his serve to advance in 78 minutes despite 12 aces and a 72 percent first-serve connection rate by the world number 15 in a losing cause.
Lu captured the first-set tie-breaker and exchanged the first service breaks of the match to open the second set, then broke Anderson in the sixth game for a 4-2 edge.
Lu hammered his fifth ace to hold for a 5-2 lead and held two games later to complete the victory.
Anderson won their only prior meeting two years ago at Delray Beach in a second-round match.
Lu seeking his first career ATP title at age 31, will next face French fifth seed Adrian Mannarino, who beat American wildcard Denis Kudla 6-2, 6-2.
Mannarino, ranked 41st, reached his first ATP final last month at Auckland. The 26-year-old left-hander connected on 76 percent of his first serve and denied both break-point chances Kudla managed in advancing.
Croatian fourth seed Ivo Karlovic needed an hour and 47 minutes to subdue 18-year-old Australian qualifier Thanasi Kokkinakis 7-6 (7/4), 7-6 (7/2).
Karlovic, 35, blasted 21 aces at the Adelaide teen, 13 of them in the first set, against only three double faults. Kokkinakis, ranked 143rd, fired five aces but had six double faults.
Karlovic, ranked 29th, has a last-eight date with US seventh seed Steve Johnson, who ousted 17-year-old Russian wildcard Andrey Rublev 6-3, 6-3.
Results on Wednesday from the third day of the ATP Delray Beach Open (x denotes seeding):
Adrian Mannarino (FRA x5) bt Denis Kudla (USA) 6-2, 6-2
Ivo Karlovic (CRO x4) bt Thanasi Kokkinakis (AUS) 7-6 (7/4), 7-6 (7/2)
Steve Johnson (USA x7) bt Andrey Rublev (RUS) 6-3, 6-3
Lu Yen-Hsun (TPE) bt Kevin Anderson (RSA x1) 7-6 (8/6), 6-3