Bernard Tomic has claimed his biggest scalp in five years, defeating world No.7 Kei Nishikori at the Cincinnati Masters les than a week out from the US Open.
Tomic, who skipped the Olympics and lost first up in Mexico last week, outlasted Rio Games bronze medallist Nishikori 7-6 (7-1) 7-6 (7-5) to book a likely quarter-final against new two-time Olympic champion Andy Murray.
Nishikori is 23-year-old Tomic’s highest-ranked win since Wimbledon in 2011, when he upset then world No.5 Robin Soderling.
However it’s the second time the Queenslander has beaten Nishikori this year. He also knocked him over in the season-opening Brisbane International, when the Japanese star was ranked No.8.
Top seed Murray was due to face Kevin Anderson in their third round clash later on Thursday (Friday AEST).
World No.21 Tomic’s serve was again on song as he approaches the final major of the year as he sent down 10 aces and was broken just once, early in the first set.
Fifth seed Nishikori wasn’t the only big gun who struggled, with an injured Rafael Nadal knocked out by teenager Borna Coric 6-1 6-3.
Nadal was visited from the trainer after the opening set, and his performance made for a sharp contrast to the Spaniard’s gold-medal doubles success last weekend at the Rio Games.
“After two months and a half and with an injury in the wrist, the normal thing is try to come back a little bit slower,” Nadal said.
The winner of 14 grand slam titles said he was “at the limit” after Rio and it was clear he was not ready.
“It was not easy to take the decision to not come here after the Olympics,” he said. “I didn’t want to be back home.”
Nadal was bothered by a left elbow injury and a too-tight strapping on his left ankle.
He now has 11 days to recover and prepare for the US Open after missing two summer months of play since quitting Roland Garros with a left wrist injury.
Second seed Stan Wawrinka also crashed out in straight sets, losing to this week’s doubles partner Grigor Dimitrov 6-4 6-4.
Steve Johnson took the top American ranking from John Isner through a knockout of seventh seed Jo-Wilfried Tsonga 6-3 7-6 (8-6).
Austrian eighth seed Dominic Thiem advanced on a walkover when Gael Monfils withdrew with back pain.