Gold, almost inevitably, was claimed by Norwegian star Jakob Ingebrigtsen who made it a double following his 3000m triumph.
Gourley's bold tactic was to track the world record holder stride for stride. It paid huge dividends as the 30-year-old held off the USA's Luke Houser in 3:39.07 to join fellow Scots Josh Kerr and Jake Wightman as a global medallist at this distance.
Coming fourth at the Europeans 14 days earlier lit a fire that ignited the Glaswegian's charge.
Gourley said: "I came here to right some of the wrongs of a couple of weeks ago at the Europeans, where I feel like I didn't compete or represent myself too well.
"This week in Nanjing I just really felt like myself and I'm happy with the result in the final. It's really just a case of staying patient.
"I had a game plan to stay at the back of the race until it started moving. I waited for the big move and then committed to it. And it worked."
Second place from the captain helped a compact British team finish fourth in the overall medal table last night, with Georgia Hunter Bell matching her Paris Olympic bronze in the women's 1500m.
Gourley emerged through the ranks at the Giffnock North club before taking a university scholarship in the USA but had to push through funding and sponsorship setbacks to become a two-time major medallist.
He added: "I was doing it for everybody that's in my corner, everyone who believes in me, and for myself because I really needed a good result.
"After a good winter's training I felt like I deserved or at least had worked really hard for some silverware."
Gourley will now jet to Jamaica to join Kerr at the new Grand Slam Track series with the Arizona-based Scot already eyeing up glory outdoors at this summer's world championships.
He added...