When it was first whispered that a woman was to take over as head chef at Gordon Ramsay's flagship restaurant in Chelsea, the man who once said the fairer sex "couldn't cook to save their lives" kept uncharacteristically quiet. The only confirmation that the UK was to see its first ever female three-star Michelin chef came when Ramsay let slip that her name was Clare.

But yesterday, Ramsay's latest protégée - Clare Smyth - emerged in combative fashion from the shadows of her new base at Royal Hospital Road with a self-assured interview – and a stinging attack on one of her key rivals who happens to be a fellow Ramsay favourite.

Asked about the comparison between herself and Angela Hartnett, the chef set to lead the kitchen at the Ramsay-owned Murano high-class eatery in Mayfair from next month, the junior chef said: "I'm not the next Angela Hartnett. I really hate it when people compare me to her because, in all honesty, Angela is a one-star Michelin chef and I'm a three-star one."

The comments, made in an interview with London's Evening Standard, were enough to cause some colleagues to splutter into their tasting spoons.

Hartnett is Smyth's senior by 10 years and was awarded her first Michelin star in 2004 when she was top chef at the Connaught in recognition of her simple, Italian-based cooking. She is well-established as a gastronomic trailblazer but Smyth's remarks merely revealed a flash of the ambitious ruthlessness that have defined her career.

The 29-year-old has come a long way since she left school in Northern Ireland desperate to make it as one of the UK's top chefs. After moving to England to study catering – working nights to gain experience – she eventually progressed to the famously innovative Fat Duck in Berkshire, where she worked for one of Ramsay's rivals, Heston Blumenthal.

Passing successfully through Bibendum – also in Chelsea – she spent three years at the St Enodoc Hotel in Rock, Cornwall's beachside answer to Sloane Square, where the emerging star won the Cornish Fish Chef of the Year award at Padstow's Fish and Chip Festival.

In 2002, she joined Ramsay's stable, and – after being identified as what Ramsay said was a "once-in-a-decade chef" – she was sent to California and eventually moved to France to gain further experience with Alain Ducasse, a hero of Ramsay's.

She was groomed from March last year at the west London restaurant and she was revealed as its top chef in November.

Yesterday, Smyth also hit out at what she perceives as sexism within the industry. "People say, 'isn't she a good chef?' and they mean for a woman," she said, adding – with a hint of the drive that led her out of the classroom and into the kitchen at 16 – "but I want to be a great chef just because I am one, not because I am a woman."