Andrey Rublev's Australian Open preparations took an unexpected hit as the top seed was dumped out of the Hong Kong Open in the second round by Fabian Marozsan on Thursday.

With the first Grand Slam of the year just over a week away, the Hungarian ranked 58th in the world won 7-5, 3-6, 6-3 in just under two hours.

The 25-year-old faces China's Shang Juncheng, 19, in the last eight at Victoria Park.

The Russian Rublev, ranked eighth, was the defending Hong Kong champion and had been pursuing a 76th tour-level quarter-final.

There was no such trouble for second seed Lorenzo Musetti of Italy, who defeated Canadian qualifier Gabriel Diallo 6-4, 6-3.

He plays Spain's Jaume Munar next. (AFP)