On-loan Arsenal striker Folarin Balogun ran through to score a remarkable 96th-minute equaliser as Reims held 10-man Ligue 1 leaders Paris Saint-Germain to a 1-1 draw on Sunday.
It looked like Neymar's strike early in the second half would be enough for PSG to take all three points despite substitute Marco Verratti being sent off shortly after that goal.
The result sees the club coached by 30-year-old Belgian-born Englishman Will Still extend their unbeaten run to 14 games between league and cup.
They remain in mid-table but have now drawn with the Parisians twice this season, their collective strength allowing a team of hungry young players to hold their own against PSG's superstars.
PSG have now dropped points in three of their four league games in 2023, and while they remain three points clear of Lens at the top of the table, their form is a concern with the first leg of their Champions League last-16 tie against Bayern Munich now little over two weeks away.
"Overall we obviously can't be satisfied with our performance. It is not a question of being worried but we need to get back to winning ways quickly and play much more as a team than we are at the moment," coach Christophe Galtier told broadcaster Amazon Prime.
"To concede a goal after 95 minutes with the number of experienced players we have -- it is damaging for us in terms of the points dropped but it is also very surprising."
In fact PSG lined up in a 4-2-4 formation at the start with Carlos Soler joining the superstar attacking trio and playing on the right wing.
- Neymar scores, Verratti sent off -
Yet they sorely missed Verratti in midfield with the Italian left on the bench in the first half as Reims looked the more dangerous side.
He came on at the break and they took the lead in the 51st minute as a Messi shot came off Achraf Hakimi and fell to Neymar, who duly converted his 17th goal of the season.
However, PSG were reduced to 10 men shortly after amid much confusion.
Reims were initially awarded a penalty for a foul by Marquinhos on Balogun in the box, but a VAR intervention led to the referee sending-off Verratti for a dangerous tackle on Junya Ito in the build-up and then cancelling the penalty for an offside.
PSG then saw Sergio Ramos head off the bar before Hakimi had a goal disallowed for offside.
It looked like they would hold on for the victory but, with the allotted five added minutes having been played, Kamory Doumbia sent Balogun away and the England Under-21 striker rounded Gianluigi Donnarumma and finished emphatically for his 11th Ligue 1 goal this season.
"We played like a team, a team that was ready, proud and who were not afraid to play here," said Still, who has not lost a game since being promoted to the role of head coach following the departure of Oscar Garcia in October.
"We had no complexes. I think the goal we conceded was a bit annoying but that is part of the game and we held on in there, maintained hope and were rewarded at the end."