Atletico Madrid tore apart city rivals Real Madrid 4-0 at home to open up the La Liga title race on Saturday in a triumph crowned by a spectacular overhead kick goal by Saul Niguez.
The champions are now four points off Real at the top and sit level with Barcelona, who visit Athletic Bilbao on Sunday, but coach Diego Simeone remains pragmatic about their chances of retaining the trophy.
"We still need to keep going match by match and see what happens," he told a news conference.
"A coach can interpret the game in many different ways but it is the players that need to execute the ideas and they were brilliant. I have to thank the players for the way they played. They were solid and serious and we need to keep going this way."
Real, who were missing key players defensively but had Cristiano Ronaldo back from suspension, began sluggishly and goalkeeper Iker Casillas was at fault as he allowed a Tiago Cardoso shot to slip under his right hand and in after 13 minutes.
The goal still did not wake up Real and they quickly conceded another through Saul, who netted in exquisite fashion having come on for the injured Koke.
Guilherme Siqueira sped down the left wing, Saul met his cross with a bicycle kick and the ball flew in off the post.
Atletico continued to create chances and Antoine Griezmann went close several times before bundling in a Saul header from close range after 66 minutes with Raphael Varane slow to react.
Mario Mandzukic further punished the Real defence with a header from a Fernando Torres cross late on.
Atletico have now beaten Real in the domestic Super Cup, twice in the league and knocked them out of the King's Cup since losing the Champions League final to their neighbours last season.
"First we have to say sorry to the fans. We were not good enough and we have to congratulate the opposition because they were better," Real full back Dani Carvajal told reporters.
"Maybe the first 30 minutes were the worst we have played at Real Madrid as we were open at the back and we didn’t create chances.
"It is early to work out what to learn from this but it was a big blow for us."
Real went into the game without injured centre backs Pepe and Sergio Ramos, as well as left back Marcelo who was suspended, and they never looked comfortable defensively.
Atletico consistently surged forward and in particular the in-form Griezmann found plenty of space.
They lost a key creative player in Koke early on but it failed to stop Atletico’s impetus while Real were strangely subdued.
Atletico continued to threaten and they ran away with the game in the second half.