The second advancement spot out of Group C at the 2022 FIFA World Cup in Qatar went down to the final seconds of the third group-stage games on Wednesday afternoon.
Poland lost 2-0 to Argentina, but a late concession by Mexico in its 2-1 win over Saudi Arabia allowed Poland to go through on goal differential.
For about 20 minutes, which felt like an eternity to both teams, Poland appeared to be headed through on the fair-play tiebreaker with two fewer yellow cards than Mexico.
Saudi Arabia's 95th-minute goal made the math as simple as it could be for the Poles, who took second behind Argentina in Group C.
Argentina may have scored four or five goals in its win over Poland, but Wojciech Szczęsny had other plans for the Albiceleste.
Argentina finally broke the deadlock out of halftime and surged in front to win Group C and set up a round-of-16 clash with Group D runner-up Australia. Poland faces Group D winner France to start the knockout round.
Australia used a victory over Denmark to gain an advantage over Denmark and Tunisia behind France in Group D's final two games, which were far less chaotic than the two in play in Group C.
Updated Round of 16 Matchups
Saturday: Netherlands vs. USA, 10 a.m. ET
Saturday: Argentina vs. Australia, 2 p.m. ET
Sunday: France vs. Poland, 10 a.m. ET
Sunday: England vs. Senegal, 2 p.m. ET
1. Argentina - 6 points
2. Poland - 4 (advanced on goal differential)
3. Mexico - 4
4. Saudi Arabia - 3
Argentina 2, Poland 0
Mexico 2, Saudi Arabia 1
The Group C drama escalated at the start of the second half in each game.
Argentina seized a lead over Poland through Alexis Mac Allister in the 46th minute.
Mexico then pulled ahead of Saudi Arabia in the 47th minute through a Henry Martin goal off a corner kick. El Tri scored again five minutes later on one of the best goals of the tournament. Luis Chávez struck a free kick from outside the box directly into the top right corner of the net.
Julián Álvarez then pulled Argentina ahead by two goals with his 67th-minute strike. That goal put Mexico and Poland level on every tiebreaker except for fair play.
Saudi Arabia then ended Mexico's time in Qatar for certain with a 95th-minute strike off the boot of Salem Al-Dawsari, who scored against Argentina earlier in the tournament.
Al-Dawsari's goal did not mean anything for Saudi Arabia—all it did was confirm that Poland would go through over Mexico.
Argentina's group win means it plays Australia on Saturday in the same side of the bracket as the United States and the Netherlands. Poland plays France on Sunday.
1. France - 6
2. Australia - 6
3. Tunisia - 4
4. Denmark - 1
Tunisia 1, France 0
Australia 1, Denmark 0
The key events in Group D took place within a few minutes of each other at the Al Janoub Stadium and Education City Stadium.
Tunisia struck for the first goal of the day through Wahbi Khazri in the 58th minute against France.
Tunisia was in second place in Group D for only a few minutes because Australia answered right away with its goal vs. Denmark.
Mathew Leckie cut a rolling shot past a diving Kasper Schmeichel to place the Socceroos into second place, where they remained after 30 nervy minutes in both games.
Australia held on to a clean sheet that was in part recorded because of its strong defensive play, led by center back Harry Souttar, and in part because Denmark could not put many significant chances on goal.
Denmark put just four of its 15 shots on target and none of the strikers it brought on to save it from elimination were particularly good. Denmark needed a win, and therefore two goals in 30 minutes, to hang on to its hopes of staying in Qatar.
Tunisia's 1-0 lead somehow held on through the final minute against France. The French rotated nine players into their starting lineup and looked disjointed throughout the first 60 minutes.
Kylian Mbappé, Ousmane Dembélé and Antoine Griezmann changed the game when they entered the field. Tunisia could not get out of its own end in the final 30 minutes. The African side needed to hold on to the win and for Denmark to come back to have a chance of moving on.
Just as Australia confirmed its spot in the final 16, Tunisia conceded to Griezmann, but after a lengthy video review, the goal was ruled out and Tunisia left the World Cup with an historic win over France.
The Frenchmen topped the group despite the loss because its goal differential was four goals better than Australia's.
Group F: Croatia vs. Belgium (10 a.m. ET, Fox)
Group F: Canada vs. Morocco (10 a.m. ET, FS1)
Group E: Japan vs. Spain (2 p.m. ET, Fox)
Group E: Costa Rica vs. Germany (2 p.m. ET, FS1)