Washington - South Africa's Kevin Anderson blasted his 21st ace on match point on Thursday to defeat Austrian top seed Dominic Thiem and advance to the quarter-finals of the ATP Tour's Citi Open.
Anderson saved a match point before dispatching the world number seven 6-3, 6-7 (6/8), 7-6 (9/7) in a thriller that lasted two hours and 46 minutes.
"He broke me a couple of times in the third set and I made a couple big serves," said Anderson. "I did a great job of making first serves and I was able to come back."
Thiem, in his first hardcourt tune-up for the US Open, fell to 0-6 lifetime against Anderson, all on hardcourts, but managed to swipe a set from his 45th-ranked nemesis for only the second time in his career.
"I don't like to play big servers in general. What can I do? The draw was not great with him in the second round," Thiem said. "It's one of those bad losses. It can't go my way all the time. It isn't easy to make this change (to hardcourt) after a long break."
Anderson saved a match point when Thiem netted a backhand to level the last tie-breaker at 6-6, then hit a forehand winner to set up a match point that Thiem erased with a service winner.
But Thiem sent a backhand wide on the penultimate point and Anderson blasted an ace wide to reach his fourth Washington quarter-final, matching his best result.
"It was a pretty good match overall. I'm satisfied with my game," Thiem said. "I didn't feel that great on my serve. I had some problems with my percentage. I just didn't get the feel of the serve."
Anderson said he can see the difference in Thiem since winning twice over him in 2014 and 2015, helped by wins over top stars Andy Murray, Roger Federer, Rafael Nadal and Novak Djokovic.
"I was able to play him before he made the huge leap that he has. It felt like a bit of a new match today," Anderson said. "Just his mentality, having beaten some of the best guys, is where he has improved the most."
Next up for Anderson is 200th-ranked Indian qualifier Yuki Bhambri, who eliminated Argentina's 100th-ranked Guido Pella 6-7 (5/7), 6-3, 6-1.
"I'd like to break back into the top 100 by the end of the year and play as many big events as possible," Bhambri said. "Hopefully I can win a few more matches here."
Anderson has never shared a court with Bhambri except in workouts.
"I've practiced with him before but that was a few years ago. He comes in and attacks. It's a challenge," Anderson said. "If I'm taking care of business on my side of the ball, then I give myself the best chance."
Anderson broke Thiem in the second game of the match and led 3-0 when a long rain delay struck. He held serve to win the set when play resumed, then missed on three break chances in the 11th game of the second set as Thiem forced a tie-breaker that was decided when an Anderson forehand clipped the net cord and landed wide.
After an early exchange of third-set breaks, Anderson double faulted on a break point to hand Thiem a 4-3 edge. But Thiem was broken in the 10th game while serving for the match.
"If you break Anderson twice in one set, you have to win it," Thiem said. "If I would have served batter I could have saved it in the third set."
Canadian third seed Milos Raonic, the 2014 Washington champion, defeated Cypriot Marcos Baghdatis 7-6 (9/7), 6-3 to book a Friday quarter-final against US eighth seed Jack Sock, who downed countryman Jared Donaldson 7-6 (8/6), 6-2.
Russia's Daniil Medvedev upset Bulgarian fourth seed Grigor Dimitrov 6-4, 6-2, firing eight aces and dropping only six points on his first serve in the 63-minute triumph, avenging a June quarter-final loss at Queen's in their only prior meeting.
Japanese second seed Kei Nishikori played Argentina's Juan Martin Del Potro in an after-midnight matchup of past Washington champions.
Results on Thursday from the fourth day of the ATP and WTA Citi Open (x denotes seeding):
Jack Sock (USA x8) bt Jared Donaldson (USA) 7-6 (8/6), 6-2
Milos Raonic (CAN x3) bt Marcos Baghdatis (CYP) 7-6 (9/7), 6-3
Daniil Medvedev (RUS) bt Grigor Dimitrov (BUL x4) 6-4, 6-2
Kevin Anderson (RSA x15) bt Dominic Thiem (AUT x1) 6-3, 6-7 (6/8), 7-6 (9/7)
Yuki Bhambri (IND) bt Guido Pella (ARG) 6-7 (5/7), 6-3, 6-1
Simona Halep (ROM x1) bt Mariana Duque-Marino (COL) 3-6, 6-4, 6-2
Andrea Petkovic (GER) bt Eugenie Bouchard (CAN) 6-2, 4-6, 6-0
Monica Niculescu (ROM x6) bt Patricia Maria Tig (ROM) 6-4, 7-6 (7/2)
Bianca Andreescu (CAN) bt Kristina Mladenovic (FRA x2) 6-2, 6-3
Sabine Lisicki (GER) bt Aryna Sabalenka (BLR) 4-6, 6-3, 6-3