Valencia forward Carlos Soler scored a hat-trick of penalties as his side beat La Liga champions Real Madrid 4-1 at home in an extraordinary match on Sunday.
Karim Benzema put Madrid ahead with a scorching strike from outside the area but Valencia replied with Soler's penalties and a bizarre own goal from Raphael Varane, inflicting a second defeat on Madrid this season and their heaviest league defeat since losing 5-1 to Barcelona in October 2018.
Madrid are fourth in the standings on 16 points after eight games, while Real Sociedad are top with 20 after nine games.
Valencia meanwhile recorded their third win of a tumultuous campaign on and off the pitch to climb up to ninth.
"After their first goal we dropped our level a bit and stopped doing everything we had been doing well. We did everything wrong, it's difficult to try and understand our performance," said Real coach Zinedine Zidane.
"There's no excuse for how we defended today. After the first goal our heads dropped and our problems kept building. Right now we are not defending as well as we used to.
"I don't think Valencia were better than us tactically today but I'm the one who needs to find solutions."
Real's preparations for the trip to Mestalla, where they had only won one of their previous six visits, were disrupted by Casemiro and Eden Hazard testing positive for COVID-19 the day before, while they lost Benzema to a muscle injury late on.
Benzema had got Zinedine Zidane's side off to a strong start with his thumping strike from distance in the 23rd minute but Valencia pulled level with the first of Soler's three penalties after a most unusual turn of events.
Soler saw his spot-kick saved by Thibaut Courtois and then hit the post on the rebound, while team mate Yunus Musah netted the loose ball, only to see the goal ruled out after a VAR review showed him encroaching in the area.
A re-take was ordered and Soler made no mistake at the second attempt.
Valencia took the lead before halftime through a freak own goal from Varane, who unwittingly sent the ball flying over his head and just over the line, the goal being awarded several minutes later following another VAR review.
Valencia's teenage forward Lee Kang-in almost struck a third early in the second period but Courtois turned his shot onto the post.
The home side kept up the momentum though and won two further penalties, for a foul by Marcelo on Maxi Gomez then a handball by Sergio Ramos.
Soler converted each time, becoming only the third player in the history of La Liga to score three penalties in a single match.
"It's great to finally get the rewards of all the hard work we have been putting in recently without getting the results we deserved," said Valencia coach Javi Gracia.
"I always felt we were competing well even if results weren't going our way and we need to keep going down this path. This result will strengthen our belief in what we are doing and give the players confidence for the games ahead."
