The 2010 Olympic champion took his sixth victory of the season in the penultimate event of the season in Sigulda, Latvia, to take an unbeatable lead in the rankings.
Loch had looked like being made to wait for his title after setting just the fifth fastest time in the opening run in Latvia.
But a stunning second run saw him overhaul Italian Armin Zoeggeler to win by 0.053 seconds on the Latvian ice.
Inars Kivlenieks took the bronze to the delight of the home fans, with the Latvian finishing on the podium for the first time.
"It almost seems as if Sigulda will be my new favorite track,” said Loch. “Last year I finished on 14th position here.
“It's a really perfect season for me. I've celebrated one success after the other In the World Cup - with two exceptions - and I took the World Championship title. It doesn't really get much better than that."
Meanwhile, in the doubles, Andreas and Wolfgang Linger took a step closer to the title as they too pipped their Italian rivals to gold in Latvia.
The German duo finished 0.239 seconds ahead of Christian Oberstolz and Patrick Gruber for their third World Cup victory of the season, giving them a 45 point lead of compatriots Tobias Arlt and Tobias Wendl, who managed third in Latvia, with just one event left.