Second-half goals from Osinachi Ohale and Asisat Oshoala gave Nigeria a stunning 3-2 win over Australia at the Women's World Cup on Thursday to leave the co-hosts in danger of an early exit.
In front of 49,156 screaming and chanting Australian fans in Brisbane, the Matildas missed a golden chance to reach the last 16 and instead now face a must-win final group game against Canada.
Nigeria top Group B and play Ireland, who are out of contention for the knockout stages, in their last group match.
After the two teams went into the break locked at 1-1 thanks to two stoppage-time goals, Ohale put Nigeria in front in the 65th minute when she headed home after Australian keeper Mackenzie Arnold could only parry a shot into her path.
Oshoala, who came on as a replacement after half-time, then took advantage of a mix-up between Arnold and defender Alanna Kennedy to get between them and fire home from an acute angle.
Australia got one back through Kennedy in the 10th minute of stoppage time but the Nigerians held on for a famous victory.
A Nigeria win seemed highly improbable after a first period which Australia dominated.
The Matildas spent much of the first half in complete control, although they struggled to break down the Nigerian defence.
Nigeria frustrated Olympic champions Canada in their opening 0-0 draw and did the same to the Matildas, who lacked the penetration that an injured Sam Kerr would have given them.
Australia finally got a reward for their dominance in the first minute of stoppage time when a poor goal kick from Nigerian keeper Chiamaka Nnadozie was picked off and Caitlin Foord's low cross was met by Emily van Egmond, who calmly slotted the ball into the back of the net.
But any hopes of taking a 1-0 lead into the break were dashed in the last play of the half, Rasheedat Ajibade cutting inside and shooting for goal, with the ball deflecting into the path of Uchenna Kanu, who beat Arnold's despairing dive.
The second half was more even but Australia were unable to break through and once Nigeria took a two-goal lead the home side never looked like coming back, despite the 11 minutes of stoppage time and Kennedy's late goal.
AFP