Reigning champions Canada got a lifeline at the Paris Games following a 2-1 last-gasp win over hosts France on the second matchday of Olympic women's football on Sunday.
Canada's quest to defend their 2021 gold medal was marred following a drone spying scandal that led to a year-ban of coach Bev Priestman and a six-point deduction by world governing body FIFA from the Olympic tournament.
The top two teams in each three groups advance, along with two best third-placed sides, leaving Canada, now led by assistant coach Andy Spence, needing maximum points in their remaining Group A matches, on top of a favourable goal difference.
The slim Canadian hopes seemed to be dashed after France's Marie-Antoinette Katoto struck in the 42nd minute following a neat passing move.
But captain Jessie Fleming equalised 13 minutes after the break. The match looked to be heading for a draw before Vanessa Gilles seized on a rebound from the goalkeeper in the 12th minute of stoppage time to fire home.
Canada plays Colombia in its final group match on Wednesday and can advance as one of the best third-place teams with a win.
Earlier in the day, Brazil missed the chance to progress after a late 2-1 loss to Japan, while Spain reached the quarterfinals with a 1-0 win over Nigeria in Nantes thanks to Alexia Putellas' late winner.
The top two teams in each three groups advance, along with two best third-placed sides.
The world champions had to wait until the closing stages in their Group C clash to break the Nigerian wall with a wonder free-kick from former Ballon d'Or winner Putellas.
Putellas struck five minutes from time beyond the Nigerian goalkeeper and defenders, who until then had frustrated Montse Tome's side.
Brazil were leading after the break but conceded two stoppage time goals to Japan, who collected their first points in Group C courtesy of Saki Kumagai and Momoko Tanikawa.
Brazil's Jheniffer low shot opened the scoring in the 56th minute after a play created by six-time Olympian Marta, who left the pitch to a standing ovation in the 84th minute.
A record six-time world player of the year, Marta has said this will be her last major tournament with Brazil. Every time that the 38-year-old got a touch on the ball Sunday night the Paris crowd cheered.
She nearly scored in Brazil's 1-0 victory over Nigeria in the team's opener, but the goal was called back by video review. But the win over Nigeria was a valuable three points for the Brazilians, who won't know their fate in Paris until after the last group matches on Wednesday.
Japan, who had missed a penalty before half-time, levelled in stoppage time thanks to Kumagai's kick from the spot after a handball by Yasmim before substitute Tanikawa netted from long range after a misplaced pass by Rafaelle.
Australia and Colombia boosted their chances of making it to the next round with their first wins in the competition.
In a goal feast in Nice, the Matildas rallied from two goals down to clinch a stunning 6-5 win over Zambia in Group B, with the Matildas' Steph Catley and Zambia's Racheal Kundananji scoring doubles, while Barbara Banda netted a hat-trick, the third to her name for an Olympic record.
Colombia edged Group A rivals New Zealand 2-0 in Lyonthanks to Marcela Restrepo's volley and a goal from Leicy Santos.
The South Americans opened the scoring in the 26th minute with a brilliant volley by Restrepo, who pounced on some sloppy New Zealand defending before Leicy Santos's fine strike off the woodwork sealed the win in the 72nd.