The contest, which was won under the practice's new name Llewelyn Davies Yeang, is for a masterplan in central Istanbul.
Yeang saw off a shortlist of serious international talent, which included Japanese star Kengo Kuma and Dutch firm MVRDV.
Yeang's winning proposals are for a major new transportation route that will link the city's east and west waterfronts to the rest of Turkey.
The scheme involves the creation of a 2km 'continuous ecological corridor' - which will feature 'eco bridges' - also serving as a new urban park for Istanbul's population.
The site, which is located between the Kucukcekmece Lake to the north and the Sea of Marmara to the south, had previously been dominated by unplanned development and transport infrastructure.
In his competition submission, Yeang claimed that this 'corridor' will make the 'area's biodiversity whole again by linking the mountain and upland ecology to the north with the coastal ecology to the south'.
Yeang was unsurprisingly delighted by the news. 'This project is hugely prestigious, especially given the international standing of the other entrants,' he said.
'We are confident that our scheme will create a new area which has its own distinct identity and is sensitive to the area's ecology,' he added.