MELBOURNE, Feb 2 (Reuters) - Dominic Thiem's Australian Open preparations got off to a slow start on Tuesday as the U.S. Open champion slumped to a 6-2 6-4 defeat to Italy's Matteo Berrettini in his opening match of the ATP Cup in Melbourne.
Blasting groundstrokes metres past the baseline, the Austrian was broken four times in a rusty display in the team-based event at Melbourne Park's John Cain Arena as world number 10 Berrettini dominated the clash of hard-hitters.
Playing his first tour match since the ATP Finals, the world number three rallied in the second set to break Berrettini for the first time but surrendered the match the way he played it, with a big swing at a backhand that thudded into the net.
Having pushed Novak Djokovic to five sets in the Australian Open final last year, Thiem is among the top contenders looking to dethrone the Serb at the Feb. 8-21 Grand Slam.
Berrettini was thrilled to take down Thiem in the Group C tie and put Italy back on level terms with Austria at 1-1 after Dennis Novak romped past Fabio Fognini 6-3 6-2 in the morning.
"I'm really happy for my performance," Berrettini said on court.
"I'm really looking forward to playing this event and the Australian Open.
"Playing for your country is something special."
The tie will be decided by the doubles players later on Tuesday. France, the other Group C team, start their tournament against Italy on Wednesday.
The winning nations of the four groups advance to the semi-finals.