The 17-year-old Scottish Boys Order of Merit leader from Bearsden survived a late onslaught from Italian Renato Paratore, one of the title favourites, to win his fourth-round match on the 19th green having earlier disposed of England boy cap Jack Singh Brar on the closing hole.
Ferguson now faces Ivan Cantero of Spain this morning for a place in the last four. "My short game really kept me in the match as I holed several good putts and my chipping was pretty deadly," he said.
He left school at 16, is now a full-time amateur; he has no plans to go to an American college but is forthright about his aims. "I just want to be the best golfer around - in amateur golf and then on the European Tour and so on. This is my first time in this championship. I did not want to play in it until I thought I had a chance of winning."
Newmachar's Adam Fisher, who did remarkably well to make the third round in the first place, lost 4&3 to European Young Masters Champion Bradley Moore.