Paris Saint-Germain have maintained their unbeaten record in Group A after coming from behind to earn a 2-2 draw with Real Madrid in Tuesday night's Champions League encounter at the Bernabeu.
Real were well on course for victory thanks to a double from Karim Benzema, but late efforts from Kylian Mbappe and Pablo Sarabia secured a point for the French outfit.
While PSG have lost their perfect record in the group, Thomas Tuchel's side have now sealed top spot ahead of their European rivals with a game to spare.
Moments before kickoff in Spain, Real's place in the last 16 was confirmed after Club Brugge could only draw with Galatasaray, and it ultimately led to a more free-flowing performance than may have been produced had they still required a result.
While PSG threatened early through two close-range opportunities for Mauro Icardi, Real soon emerged as the better team and deservedly took the lead thanks to a fine team goal finished off by Benzema.
Some sharp play from Eden Hazard set things in motion and after Isco had fired against the post after meeting Federico Valverde's cutback, the Frenchman was on hand to send a smart finish into the far corner of the net.
Hazard was producing arguably his best performance since his arrival from Chelsea in the summer, although it was Toni Kroos who twice went close with good efforts from the edge of the area.
Dani Carvajal and Marcelo also tested former Real stopper Keylor Navas, although PSG came more into the contest during the final 15 minutes with Marco Verratti having a long-range effort pushed away by Thibaut Cortois and Mbappe firing too close to the goalkeeper from a tight angle.
Just before the half-time whistle, the visitors thought they had earned a penalty when Courtois tripped Icardi inside the area, with the place where the infringement took place only being confirmed by VAR.
However, after the referee had taken the opportunity to watch the video screen at the side of the pitch, he withdrew a red card controversially handed to Courtois and overturned his call to give a penalty due to a soft foul on Marcelo on the halfway line.
Thomas Tuchel chose to introduce Neymar at half time, but it was Real who stormed out of the blocks after the restart, with Benzema having a close-range effort blocked by Navas.
While PSG continued to have flurries forward, the better chances were being created by Real, firstly through Kroos who saw another 20-yard strike go narrowly off target.
Moments later, Navas was back in the action to claw away Isco's flick at the near post, but Real's momentum was halted when Hazard was forced off with an ankle injury.
Gareth Bale received a mixed reaction as he replaced the Belgian, but the winger played his part as Real extended their advantage with just 11 minutes remaining.
The Welshman's header led to the ball going into the path of Marcelo, and the left-back's cross was perfect for Benzema to power a header into the roof of the net from six yards out.
However, while there was a feeling that PSG were beaten, the visitors were gifted a way back into the contest by Raphael Varane and Courtois, who got in each other's way to allow Mbappe to divert the ball into the net from virtually on the line.
The French giants had the momentum and their equaliser arrived just over two minutes later as the ball found its way to Sarabia, who was waiting on the edge of the area.
While the former Sevilla man had the time to take a touch, he instead found the top corner of Courtois's net with a stunning half-volley.
Both teams had further opportunities during four minutes of added-on time, with Bale almost stealing the headlines with a brilliant free kick which struck the post.
However, after that near miss, the teams were left to share the spoils, with PSG likely being more satisfied with a point than their hosts.
REAL MADRID (4-3-3): Courtois; Carvajal, Varane, Ramos, Marcelo; Valverde (Modric 76'), Casemiro, Kroos; Isco (Rodrygo 82'), Benzema, Hazard (Bale 69')
PARIS SAINT-GERMAIN (4-3-3): Navas; Meunier, Thiago Silva, Kimpembe, Bernat; Gueye (Neymar 46'), Marquinhos, Verratti; Di Maria (Draxler 75'), Icardi (Sarabia 75'), Mbappe