Tennis fans have accused Channel Nine of undermining the talent of an underdog Hsieh Su-Wei during her unlikely win against Bianca Andreescu in the second round of the Australian Open. 

Hsieh delivered one of the first major upsets of the 2021 tournament sending eighth-seeded Canadian and 2019 US Open champion Bianca Andreescu packing with a 6-3 6-2 second-round victory on Wednesday.

Despite the Taiwanese star's dazzling play on the court many viewers were frustrated all the commentators could talk about was Andreescu. 

The Canadian endured a 15-month absence from the game due to injury and was one of the 72 players unable to train during hard quarantine in the leadup. 

Hsieh is known for knocking off top players in Grand Slam tournaments with her entertaining style of play - opting for deep, angled groundstrokes and an array of slices.

She ousted Garbine Muguruza at the 2018 Australian Open on the way to the fourth round and dumped then world number one Simona Halep out of Wimbledon in the same year.

In 2019 she then beat Japanese superstar Naomi Osaka and Germany's Angelique Kerber. 

Fans online said Hsieh should have been given more credit by the commentary team. 

'The commentator need to give credit to Hsieh, she outplayed Andreescu. The disrespect of Hsieh is repulsive,' one viewer wrote. 

'Commentators freaking out that Hsieh could play well against Andreescu is comedy,' added another. 

'Commentary was arrogant bordering on offensive,' a third added. 

And the awkwardness didn't stop there - with Hsieh offering a token of advice during her on-court post match interview. 

Congratulated by the interviewer Brett Phillips at Rod Laver Arena for 'still going strong' at the age of 35, Hsieh held a finger to her lips, shook her head and laughed.

'Just little reminder (for) you. In Asia we normally don't say the girl's age in the public,' she said, triggering laughter and applause in the stands.

'You look like you've got plenty more years left,' Phillips persisted, digging his hole a bit deeper.

'I look a little bit younger but I try my best standing here. Thank you for your comment,'' she replied. 

Hsieh is also the world's top-ranked doubles player and uses an unorthodox double-sided game.

Andreescu looked outplayed by Hsieh from the outset with no apparent plan, she doubled down on the power game and the unforced errors piled up as she slumped to a 5-2 deficit in the second set. 

Her opponent opted for angled shots and spin rather than relying on power shots with the 'intelligent' strategy paying off. 

Andreescu saved two match points on serve but bowed out meekly with a double-fault on the third. 

Hsieh can now advance to a third round clash against either Venus Williams or Sara Errani. 

Daily Mail Australia has contacted Nine for comment.