Meghan Markle won over an unexpected wave of admirers with her long-awaited appearance on MasterChef Australia on Sunday night.

The Duchess of Sussex, 44, stepped into the famous kitchen as a special guest judge – and viewers who admitted knowing little about her said they were pleasantly surprised by her warm manner and thoughtful feedback.

While Meghan has long been one of the world's most polarising public figures, fans said the cooking competition allowed them to see a markedly different side of her.

Social media users described the former Suits actress as 'graceful', 'down to earth' and 'genuinely nice', with some declaring she was one of the program's more impressive celebrity guests.

The episode was filmed in Melbourne during Meghan and Prince Harry's Australian visit in April and challenged contestants to prepare a dish 'fit for a Duchess'.

Poh Ling Yeow teased the arrival of 'MasterChef royalty' before introducing Meghan to the stunned cooks as 'the Duchess of Sussex'.

Meghan appeared relaxed as she entered the kitchen and warmly greeted the judges and contestants before settling in to taste their creations.

The aspiring chefs were asked to draw inspiration from ingredients said to be among the Duchess' favourites, including strawberries, lemons, artichokes, carrots and Brussels sprouts.

They were also given access to edible flowers, which have become closely associated with Meghan's Netflix series, With Love, Meghan.

Despite the anticipation surrounding her appearance, the Duchess did not attempt to dominate proceedings.

Instead, she listened carefully as the contestants explained their dishes and offered calm, encouraging observations about their food.

Her measured approach appeared to change the minds of several viewers, including some who confessed they had not previously followed her career.

'I'm American so take this for what it's worth, but I thought MM did a great job,' one viewer wrote.

'Her comments were actually insightful and you could tell she has some knowledge.'

Others quickly agreed, with one replying: 'I'm with you. I don't follow her at all, probably couldn't identify her from a photo, but she was way better than, say Katy Perry, who was a guest once.'

The viewer added that Meghan 'seemed like a genuinely nice person' who provided relevant feedback while still making the contestants feel good about their efforts.

Another fan also compared the Duchess favourably with Perry's memorably chaotic stint on the show.

'Good episode,' they wrote. 'MM was so much more refreshing than when Katy Perry was a guest.'

The praise continued on MasterChef Australia's official Instagram page, where comments about Meghan were overwhelmingly enthusiastic.

'She is so graceful,' one admirer wrote.

'The people's princess,' another declared.

A third fan said: 'Great job Meghan & MC AU. Congrats to all the contestants.'

Another wrote: 'Love Meghan, so down to earth,' while one excited viewer joked: 'I'd cheer too if Meghan walked into my kitchen.'

Meghan also delighted the contestants when her husband, Prince Harry, 41, made an unexpected FaceTime appearance during judging.

'G'day! What's going on? Have I interrupted something important here?' the Duke joked as his face appeared on the screen.

A smiling Meghan told him they were in the middle of sampling the contestants' dishes.

'We have four incredible cooks here!' she said. 'It's amazing, they are so talented!'

She explained that Harry was in Canberra meeting veterans while she filmed the program in Melbourne.

'I can see the chandeliers in the background; they look very nice… wonderful!' Harry responded.

Meghan then turned the camera around to give him a look at the dishes.

'I wish you could try this,' she said. 'These dishes are fantastic, really great dishes. There's a hot sauce and it is so good!'

She then teased her husband about his tolerance for heat, adding: 'I think it might be too much for you though – it's spicy.'

'I will leave you to enjoy it. All is well here, see you later,' Harry replied before waving goodbye.

The studio audience burst into applause following his brief appearance.

'He's a charmer, isn't he?' Meghan said with a shrug.

The contestants were stunned to find themselves speaking to the Duke of Sussex in the middle of a cooking challenge.

'That's crazy, wow!' Aaron said. 'The last thing I was expecting was Prince Harry on a FaceTime call.'

Dot was equally amazed by the surprise cameo.

'Oh my gosh, just when you think you're at the peak, we're FaceTiming Prince Harry!' she said. 'This is nuts.'

The affectionate exchange also gave audiences a more personal glimpse of the Sussexes' relationship, with the pair appearing playful and at ease despite being in different cities.

Meghan's friendly rapport with Poh was another talking point after the broadcast.

The two women appeared to hit it off immediately, laughing and chatting comfortably throughout the episode despite rumours before it aired suggesting there had been tension between them.

Their easy chemistry seemingly put an end to the speculation, with no indication on screen of the alleged behind–the–scenes feud.

Network 10 first announced Meghan's guest judging role in April, describing her as a 'passionate foodie' and revealing that the appearance had been kept secret from the contestants.

Her unexplained absence from part of the Sussexes' Australian itinerary was subsequently revealed to have been caused by the top-secret filming commitment.

The culinary role was a natural fit for the Duchess, who previously ran lifestyle blog The Tig and has made cooking, gardening and entertaining central to her more recent projects.

However, it was not merely her interest in food that caught viewers' attention.

Fans said her appearance showed a softer, more relaxed side of Meghan than the one frequently portrayed in headlines.

Rather than delivering vague praise, she impressed viewers by offering constructive observations while remaining sensitive to the pressure facing the contestants.

For those who had expected a more formal royal cameo, her laid-back sense of humour and easy exchanges with the cooks came as a surprise.