Eating sushi and sashimi at midday is now as common as having a lunchtime sandwich. But until recently it was rare to find many outlets for truly upmarket Japanese cuisine.

Today, as the first Japanese restaurant is named best new Restaurant in the Which? Good Food Guide London, there is a sign that the Nobu chain has some serious rivals.

The authors of the Which? Good Food Guide London said that the Sake No Hana restaurant, in Mayfair, central London, had provoked more reader comments than any other. One described it as "pure and unadulterated joy for people who understand and love Japanese food"; another dubbed it a "temple of cool".

Alan Yau, the restaurateur, said: "We haven't been open that long, so it's a really pleasant surprise. There is now a market for top-end Japanese food, but that simply wasn't the case 10 years ago." He said that it was Nobu, the London restaurant which celebrated its 10th anniversary last year, which first put the idea of quality Japanese cuisine on the map. "Nobu opened the door for this", he said. "They taught people how to eat Japanese food at a fine dining level."

Mr Yau said he had been travelling to Japan every month to ensure the venture was thoroughly researched for its authenticity. The restaurant took the bold move of taking wine off the menu, and serving 65 different varieties of sake and hiring a sake sommelier.

This is not the first accolade Mr Yau has received for his cuisine. Following the success of his chain of Wagamama restaurants, which popularised eastern cuisine, he was made an OBE for services to the restaurant industry in 2006. Sake No Hana is the third top-end restaurant opened by Mr Yau – his earlier ventures, Hakkasan and Yauatcha, have both been awarded a Michelin star.

Chain restaurants such as Yo Sushi and Itsu have been springing up across the capital, offering Japanese food at high-street prices, but high-end eating has been harder to come by. In recent years, however, quality Japanese cuisine has gradually been permeating the London scene, with swanky eateries such as Zuma and Nobu springing up in the capital.

Elizabeth Carter, consultant editor of the Which? Good Food Guide, said: "The first Japanese restaurant opened in the 1970s, but now they've captured everyone's imagination." She believes the reason high-end Japanese cuisine has taken off is that British eaters are becoming more health-conscious. "People like to eat lighter now than they used to," she said. "In the old days it was lots of cream and alcohol-laden sauces, but customers don't want that now, they want something lighter. Japanese food is light and healthy, and that fits in with people's lifestyles now."

The Japanese cookery book author Kimiko Barber said she was excited by the way Japanese food had become so popular. "When I came to this country in the 1970s there were only five Japanese restaurants in England, so for me it's a dream come true to see sushi sold next to smoked salmon sandwiches.

"Companies such as Yo Sushi and Wagamama have brought Japanese food to the general public, which is great, but now there is an increasing demand for top end restaurants".

But while Barber, who has recently been to review Sake No Hana, said she was glad to see Japanese food put on the map by the award, she was disappointed that it did not go to another restaurant. "I don't think they deserve it", she said. "The food is very mediocre, and I have never seen such ugly sushi in my whole life."

Good Food Guide winners

* Best new restaurant: Sake No Hana, Mayfair

* Best value for money: Tom Ilic, Battersea

* Best budget restaurant: Viet Grill, Shoreditch

* Best gastropub: Carpenter's Arms, Hammersmith

* Best set menu: Wild Honey, Mayfair

* Best vegetarian: Manna, Primrose Hill

* Best for breakfast: Roast, London Bridge

* Best wine list: The Square, Mayfair

* Best fish restaurant: One-O-One, Knightsbridge

* Best up-and-coming chef: Tristan Mason, formerly of Orrery, Marylebone