Mr Sanderson (28), co-owner of Lalaland Lounge Bar Wanaka, will be the only South Island representative in the New Zealand final of the Diageo World Class cocktail contest, billed as the bartending industry's biggest and most prestigious event.
The winner will compete against national champions from more than 50 countries at the global final in Great Britain from July 28 to August 1.
Mr Sanderson finished third in last year's inaugural New Zealand battle - won by former Queenstown bartender Jason Clark.
Following a long period working in Australia's hospitality industry, Mr Sanderson moved to Wanaka to fill a gap in the market with his craft cocktail bar.
Further establishing Lalaland's name in the industry was good motivation to try for the national Diageo title again, he said.
''And to take some of the shine off the North Island and Auckland and Wellington, who seem to get all the love when it comes to these sorts of competitions.''
During the past three months, New Zealand entrants have completed a series of challenges, including creating a cocktail list to suit their clientele, throwing a themed party, sitting a written test and having their bar ''mystery-shopped''.
''It's not just about who can make the best drink, it's also about who knows their audience, who can organise a party, who can be a manager.''
Mr Sanderson finished first in all the challenges, which he said was a ''bit of a confidence boost''.
However, on Monday all five finalists' scores would be reset.
''It's a blank slate, so I guess it's just see how everyone goes under the pressure.''
At Auckland, bartenders will make their signature cocktail for more than 100 guests over a two-hour period and compete in a speed challenge, mixing multiple cocktails in a matter of minutes.
Mr Sanderson's signature drink, Breakfast at Tiffany's, is a blend of Tanqueray No. 10 gin, a pink grapefruit and chamomile tea reduction, fresh citrus, egg white to give a ''fluffy'' consistency, a dehydrated citrus and candied rhubarb garnish and a grapefruit and chamomile mist over the top ''like a perfume''.
It is the top-seller at Lalaland.
Mr Sanderson said the competition was well-established overseas and offered some ''huge'' opportunities.
The winner of the Australian battle gets $100,000 to open a bar.
Last year's UK contenders made ''mile-high cocktails'' aboard a Boeing 747 and the 2013 global final took place during a five-day cruise in the Mediterranean.
''So you can get an idea of the scale of the competition ... it's quite exciting to be part of it at the start of it in New Zealand, where you can see so much progress every year.''
