Ross, from Ulster, dominated the opening two sets, taking the first 7- 1 and then securing the second 7-4, before Gourlay, the world No 5, got off the mark with a 7-0 whitewash in the third set.
Gourlay, the Scot who won the title in 1996 champion, then opened up a 4-1 lead in the fourth set but Ross hit back and helped by a slice of luck, tied the set at 6-6.
A relieved Gourlay secured the set-winning shot on the next end and he then went on to complete his magnificent fightback when he won the deciding set 7-4.
"My control of weight in the opening two sets was dreadful," the Scot said. "I continually bowled short and put myself under all sorts of pressure but thankfully I found my touch just before it was too late."
Ross said: "In the last three sets David started getting his opening bowls closer than mine and that's what swung the match in his favour."Reuse content