Kadeisha Buchanan's first international goal was enough for Canada as it beat Cameroon 1-0 in its opening Women's World Cup fixture.
Canada had over 70 percent of possession in the opening half of the first World Cup meeting between the sides, but it took them until the 45th minute to craft a breakthrough in Montpellier.
Nichelle Prince's effort against the post looked to have summed up a frustrating first half for the world's fifth-ranked side, but Buchanan's thumping header had them in front moments later.
Canada was almost made to pay for another Prince miss midway through the second half, but Claudine Meffometou failed to turn her close-range header home as Kenneth Heiner-Moller's side held firm to move top of Group E, which also includes Netherlands and New Zealand.
Making its seventh successive appearance at a World Cup, Canada started brightly, and might have had the lead had captain Christine Sinclair directed her third-minute header on target.
But with the post having come to Cameroon's rescue when it denied Prince an opener, its resistance was broken on the stroke of half-time.
Buchanan rose highest to meet a corner at the back post and, under little pressure from Cameroon's defense, made no mistake in heading home.
45' GOAL! Kadeisha Buchanan#CAN 1:0 #CMR#CANWNT #TogetherWeRise #DareToShine #CANCMR pic.twitter.com/9rXJagC278
— Canada Soccer (@CanadaSoccerEN) June 10, 2019
Cameroon did well to stifle any Canada momentum after the restart, though Prince should have done better when she was put through on goal, prodding wide on the volley.
Meffometou had a chance to ensure Prince lived to regret that miss in the 70th minute, but unlike Buchanan in the first half, she lost her composure and headed wide from six yards out to let Canada off the hook.
Canada looked set to bundle in a second in the 88th minute, though Meffometou was on hand to hook Sinclair's scuffed attempt clear off the line.
Key Opta Facts
— Canada has won its opening game at the Women's World Cup in back to back editions having failed to win any of its five tournament openers beforehand (D1 L4).
— Cameroon registered just 26.3 percent possession in this game — since the start of the 2011 tournament, only Ecuador against Switzerland (25.4%) have had less possession in a Women's World Cup game.
— Canada is unbeaten in its last nine games across all competitions (W6 D3), since a 0-2 defeat against USA in October 2018, keeping eight clean sheets in the process.
— Buchanan's winner for Canada was her first goal at the Women's World Cup in what was her sixth appearance in the competition.
— At 35 years and 363 days, Sinclair became the oldest player to represent Canada at the Women's World Cup.