Australia's Jordan Thompson has recorded one of the best wins of his career, beating former number-two ranked Alexander Zverev in the opening round of the ATP's Japan Open in Tokyo.
A fortnight a suffering a disappointing first-round loss to world No.148 Terence Atmane of France at the Shangahi Masters, Thompson ousted the third seed 6-3 6-4 to set up a round-of-16 clash with in-form American left-hander Ben Shelton or local qualifier Taro Daniel.
"I'll get better," 29-year-old Thompson said after his 95-minute upset.
"Obviously I felt it was pretty good today, but we will see how I recover."
German world No.9 Zverev had won the only previous meeting against Thompson, also on hardcourt in Washington DC six years ago, but was broken in the fourth game en route to dropping the first set.
The Tokyo Olympics gold medal winner two years ago got the jump in the second, breaking for 2-0. But the 26-year-old with 21 tour titles to his name relinquished that advantage immediately.
World No.60 Thompson, who had six aces and no double faults, then broke for a third time in the match in the ninth game before serving it out.
"He's a quality player, I don't need to say what he's done in his career," Thompson said.
"When I get on the court with these guys I got to believe that I can win. I enjoy the challenge."
The three other Aussies in singles action on Monday were beaten.
Aleksandar Vukic succumbed 7-6 (7-3) 6-7 (2-7) 6-2 to world No.17 Felix Auger-Aliassime of Canada in a near three-hour battle.
Max Purcell lost 7-5 6-4 to American world No.37 Mackenzie McDonald and Chris O'Connell went down in three sets to Sebastian Ofner of Austria, 6-7 (2-7) 7-6 (7-5) 7-5.
Two more Australians are in action on Tuesday with fourth seed Alex de Minaur facing Brit Jack Draper and Alexei Popyrin taking on Russian seventh seed Karen Khachanov.
