The practice saw off a wealth of the country's biggest architectural hitters in the contest - run by developer Urban Splash - to transform the 4ha site in the Cheshire town.
Among the names to have missed out are Sutherland Hussey, Make, John McAslan + Partners, Terry Pawson Architects, Springett Mackay, and Broadway Malyan.
John Miller and Partners, which designed the nearby Brindley Arts Centre, had also made it onto the final shortlist of eight battling it out to revamp the old-town area.
The AHMM scheme, which includes plans for a mixture of residential, retail and leisure uses, will be worked up in collaboration with Halton Borough Council, and a planning application is expected to be submitted within the next six to 12 months.
The site is currently occupied by a council car park and a former soap and alkali works.
Backed by English Partnerships, the project could start on site as early as next spring.