Bayer Leverkusen claimed a remarkable 3-0 statement win over champions Bayern Munich on Saturday as they went five points clear of them at the top of the Bundesliga and took their unbeaten season record to 31 games.
Full back Josip Stanisic, who is loan at Leverkusen from Bayern, opened the scoring in the 18th minute. Alejandro Grimaldo fired the second five minutes after the restart, and Jeremie Frimpong wrapped up the topper in stoppage time.
Xabi Alonso's Leverkusen grew into the game after Bayern had dominated the first minutes. The champions improved again later in the second half but failed to seriously threaten, with their league leading striker Harry Kane no factor.
Leverkusen, who have never won the Bundesliga, are the only unbeaten team in Europe's top five leagues and can achieve a title treble.
They have won 17 of their 21 Bundesliga matches, all four in the German Cup where they have reached the semi-finals, and all six in the Europa League group stage for a last-16 berth.
But Bayern have won the last 11 Bundesliga titles and have responded to challenges on several occasions in the past. There are still 13 matches to be played, and coach Thomas Tuchel vowed that "we will not throw in the towel."
Alonso would not accept the role of big title favourites, telling Sky TV: "We have to be patient and keep our feet on the ground. Let's talk in May.
"We wanted to be competitive. You have to be compact at the back. The first goal was important. The lads worked very hard. We had a lot of chances while not allowing Bayern chances," the Spaniard said
Midfielder Robert Andrich said: "We were aggressive and did good things from the kick-off. It was a very deserved win."
Bayern forward Thomas Müller questioned the dedication of his team-mates, saying: "I miss the freedom in our matches that we show in training. You may feel the pressure but it is to give you energy."
Tuchel spoke of "individual mistakes" that helped Leverkusen win and that his team lost the ball too often while in transition.
Bayern had defenders Kim Minjae and Dayot Upamecano back from the Asian Cup and injury, respectively, and captain Manuel Neuer was between the posts after not training all week due to a knee problem.
The champions dominated possession but without threatening before Neuer was called into action for a first time after 10 minutes on Amine Adli's shot.
Neuer and Upamecano then jointly managed to clear another Leverkusen effort but that led to a throw-in, and Robert Andrich's low ball across the goalmouth was converted at the far post by Statisic who was mobbed by his team-mates but refused to celebrate himself.
The lead boosted the hosts, with Neuer denying Nathan Tella's volley and Upamecano making a key challenge against Adli, before Leroy Sane aimed wide on Bayern's first telling chance shortly before intermission.
Things got worse for Bayern five minutes after the restart when Grimaldo played a stunning one-two with Tella and smashed into the near corner past Neuer for 2-0.
Tuchel brought on the likes of Müller and Joshua Kimmich, which gave them more possession but the danger was at the other end when Grimaldo's corner-kick hit the top of the crossbar and Frimpong was denied by the post.
Frimpong then completed a memorable night when he struck into an empty net from a right angle after Neuer had come forward for a Bayern corner kick.
The match started several minutes late because fans threw objects onto the pitch in ongoing protests against a planned German Football League (DFL) investor.
The game between Union Berlin and Wolfsburg was close to being abandoned over the protests and was interrupted for half an hour mid-way through the first half. Union won 1-0 to move six points clear of the danger zone.
Lois Openda failed to convert a late penalty as fifth-placed RB Leipzig drew 2-2 in Augsburg, and Eintracht Frankfurt were held 1-1 by Bochum.
Visiting Heidenheim spoilt Werder Bremen's 125-year club anniversary with a 2-1 victory while Borussia Mönchengladbach were held 0-0 by bottom club Darmstadt.
Borussia Dortmund beat Freiburg 3-0 on Friday, and Sunday's games are VfB Stuttgart v Mainz and Hoffenheim v Cologne.
