Stefanos Tsitsipas thrashed Alexander Zverev in a battle of the big guns at the ATP Cup on Sunday, inflicting a second successive defeat on the German in his warm-up for the Australian Open.

On the third day of the inaugural 24-nation team event in Sydney, Brisbane and Perth, world number 11 David Goffin was another loser, along with Italy’s Fabio Fognini, ranked one place below him.

Greek star Tsitsipas, who won the 2019 season-ending ATP Finals in London and is now ranked six, was nowhere in comparison to Zverev, who only began hitting balls a week ago after an off-season curtailed by a lucrative exhibition tour. The lacklustre German world number seven sent down 10 double faults and made just 45 percent of his first serves, a worrying sign ahead of the opening Grand Slam of the year.

“I worked very hard for this win, I found solutions, found my rhythm and my pace and knew what I was doing on court,” said impressive 21-year-old Tsitsipas after his 6-1, 6-4 walloping in Brisbane.

“I was serving pretty okay and played clever again. I managed to stay calm and positive in my head.”

The 24 countries are split into six groups, with the top eight from the round-robin going onto the knockout phase before one is crowned the winner.

The Grigor Dimitrov-led Bulgaria won their second tie in a row, beating Moldova 2-1, to be in a commanding position in Group C, while Australia also made it two-out-of-two in Group F with De Minaur again on fire in their 3-0 sweep of Canada.