McLeod, playing in front of a hometown crowd, made five leaping or diving saves off bullet drives in the first half to hold off a South Korean team that held the edge in play but couldn't finish.
In the space of three minutes McLeod stopped two shots from Korean forward So Yun Ji.
At the 32-minute mark Ji curled a shot around the wall on a free kick toward the lower corner that a diving McLeod just got a hand on to direct away.
Three minutes later she went vertical to get her fingertips on a Ji blast from 25 feet out.
"She's a phenomenal player," McLeod said of Ji.
"She tried to catch me off guard a few times.
"They did well in our end and we did well to keep them at zero."
Canada struggled in the first half to get the ball up to striker Sinclair on a chilly night before 12,746 fans.
Canada didn't get its first shot on net until the 18-minute mark.
But when the Canadians found the net, they made the most of it.
Sinclair opened the scoring in the 23rd minute, heading a Diana Matheson corner kick off the far goalpost past Korean keeper Min Kyung Jun.
Canada scored again at the 39th minute on a tic-tac-toe play that began when Matheson lobbed the ball in front of the net. Defender Carmelina Moscato flicked it to Melissa Busque, who headed the ball into the path of Timko, who then kicked the ball in from in close.
Forward Adriana Leon took a pass from Kaylyn Kyle from 10 feet out and directed a low shot past Jun to make it 3-0 at the 69-minute mark.
Stephanie Labbe replaced McLeod in the second half.
McLeod said the win was gratifying given the team is just getting back together after a long break.
"We're not game fit. We've come off a month and a half break, so I think the last 20 minutes of the game I think we showed the most character, staying compact."
Head coach John Herdman said the team played well considering the long layoff, but said McLeod came through when it counted.
"What a goalkeeper. Arguably the best in the world," he said.
"(The Koreans) deserved a goal or two. It could've been a closer match. I suggest we've still got a little work to do.
"In the flanks and the wide areas we looked a little sloppy at times.
"The Koreans were technically brilliant at times. That's what we're aspiring to."
The game is considered the start of the national team tune up for the 2015 World Cup.
Herdman said next step is a four-month development camp.
"All the hard work starts now," he said.