Chinese rising star Buyunchaokete suffered a straight sets defeat to qualifier Hady Habib, crashing out of the Australian Open men's singles draw in a first round upset on Sunday.

219th-ranked Habib served strongly and overcame a late rally from Buyunchaokete to record a 7-6 (4), 6-4, 7-6 (6) victory in two hours and 31 minutes.

The 22-year-old Chinese is still seeking a maiden victory at a Grand Slam having made his debut at last year's US Open, where he lost to Norway's Casper Ruud in the first round.

His match against Habib was significantly delayed due to heavy rain that lashed Melbourne, leading to the suspension of play on the outside courts.

It did not start until the evening, with the muscular Buyunchaokete entering as the favourite but wary against Habib, who had advanced to the main draw after three rounds of qualifying.

That made the United States-born Habib the first men's Lebanese player to reach a Grand Slam singles draw.

Habib and 67th-ranked Buyunchaokete showcased their serving prowess with a tiebreak needed to decide the opening set.

An inspired Habib fed off the energy from his supporters in the crowd as he produced deft touch at the net before clinching the tiebreak with a brilliant forehand winner.

The second set appeared to be following the same script until the 10th game when Buyunchaokete was broken by Habib, whose powerful groundstrokes hit the lines with precision.

Habib seemingly crushed Buyunchaokete's spirit by breaking early in the third set, but he could not serve out the match in the ninth game. It came down to a thrilling tiebreak with Buyunchaokete having a set point after leading 6-5.

But Habib stepped up under pressure to win the next three points and claim his first victory at a Grand Slam. He will play 14th seed Ugo Humbert or Matteo Gigante in the second round.