Chiamaka Nnadozie saved a penalty kick by Canadian captain Christine Sinclair in in the 50th minute, as Nigeria emerged with a surprising 0-0 draw against Canada at the Women's World Cup in Melbourne.
The game was the opener for both teams in Group B. Australia tops the group after beating the Republic of Ireland 1-0 on Thursday.
Canada captured the gold medal at the Tokyo Olympics in 2021 and are ranked seventh in the world by FIFA. Nigeria are ranked 40th.
Nigeria ended the game with 10 players after Deborah Abiodun received a red card deep in second-half stoppage time for a late, high challenge on the shin of Ashley Lawrence.
The key moment in the game came early in the second half. After a video review, Francisca Ordega was ruled to have fouled Sinclair in the penalty area. However, Nnadozie dived to her left and knocked away Sinclair's low penalty kick.
Sinclair, 40, was attempting to become the first player - male or female - ever to score in six World Cup tournaments. She is the all-time leader in international goals with 190.
"We've got to move on very quickly, you know, you can get lost and be really down on that," said Canada coach Bev Priestman, whose team next faces Ireland in Perth on Wednesday.
"Of course the team and I am devastated. We didn't get three points. But at the end of the day we got one and we took two from another team."
Both sides had their chances but 40-year-old Sinclair, who came off ashen-faced in the 70th minute, was perhaps the most frustrated, having also missed a good opportunity when she fired wide in the ninth minute.
Nigeria, the lowest-ranked team in the group, defended desperately to hold out the Canadians, and a roaring Nnadozie slumped to her knees, pumping her fists in celebration after the final whistle.
"I'm probably going to embarrass her, but I think she’s one of the best young goalkeepers in the world today," said Nigeria coach Randy Waldrum.
"I think Chiamaka's save really kind of lit the fire and made us realise there's still something to play for."
Nigeria's joy was tempered by a red card, upgraded from yellow by VAR, for midfielder Deborah Abiodun after a studs-up tackle deep in stoppage time. She will miss their next game against Australia.
Canada's midfield dynamo Jessie Fleming was ruled out injured before the match and her absence contributed to the team's clunky transition play.
Sinclair, however, found space on the edge of the area early and blasted wide of the right post, with Jordyn Huitema heading well wide later in the first half.
The Africans also struggled on attack, but Ifeoma Onumonu forced goalkeeper Kailen Sheridan into a diving save at the far post after unloading from long range in the 23rd minute.
Sheridan came close to gifting Nigeria the lead when she charged off her line 10 minutes from the break, missing the ball with her attempted clearance.
But Nigeria striker Asisat Oshoala's cross at the near post was blocked and both teams went to the break frustrated.
Canada's frustration spiked after the interval as Sinclair was brought down in the box by Francisca Ordega, the penalty awarded by VAR.
Nnadozie blocked Sinclair's tepid shot and later denied substitute Evelyne Viens, who latched onto a header in the area and volleyed straight into the keeper's arms.
