Berlin (AFP) - Bundesliga champions Bayern Munich stormed back from three goals down to win 4-3 at Mainz on Saturday, ahead of their Champions League semi-final first leg at Paris Saint-Germain.

After wrapping up another Bundesliga title last weekend and with an eye on Tuesday’s trip to the French capital, Bayern coach Vincent Kompany made sweeping changes to his team.

Mainz took advantage and cut through Bayern to lead 3-0 at half-time thanks to goals from Dominik Kohr, Paul Nebel and Sheraldo Becker.

Bayern introduced Harry Kane and Michael Olise for the second half and then also brought on Jamal Musiala, turning the match on its head.

Nicolas Jackson ignited the comeback before Olise and Musiala struck to bring Bayern level. Kane’s 33rd league goal of the season with seven minutes to go won it for the visitors.

“What went wrong in the first half? Everything. But in the second half, we accepted the fight,” Kompany told reporters.

“We’re already champions and you could imagine the team being OK with a 3-0, 3-1 defeat, but that wasn’t the case. We celebrated like we saved ourselves from relegation.”

With most of the team that started Wednesday’s 2-0 German Cup semi-final win over Bayer Leverkusen on the bench, Mainz broke the deadlock when Kohr scored from close range after a scuffed clearance from Bayern goalkeeper Jonas Urbig.

Mainz doubled their lead just before the half-hour mark, Nebel tapping in a rebound. The hosts added a third moments before the break through Becker.

But Kompany’s decision to throw on his attacking stars swung the game in Bayern’s favour.

Jackson turned in a Konrad Laimer cross and Olise scored with a superb curling effort from the edge of the box to cut the deficit to 3-2.

Olise set up Musiala to equalise, with the Germany midfielder then laying one on for Kane to put Bayern ahead and seal a remarkable comeback.

- Leverkusen stay in top-four hunt -

Elsewhere, Patrik Schick bagged a brace as Leverkusen downed derby rivals Cologne 2-1 away to keep their top-four hopes alive.

The win took Leverkusen a point behind Stuttgart, who play Werder Bremen on Sunday.

The Czech striker converted a penalty late in the opening half before adding another after the break, turning in a Nathan Tella pass to finish off a length-of-the-field counter.

Schick, who now has six goals in his past five league games and seven in his past eight clashes against Cologne, praised his team’s fight.

“This win was really important for us. We need points and we’re fighting for the Champions League. It wasn’t perfect today, but we’re happy with the three points,” Schick told DAZN.

Heidenheim kept their slim hopes of evading the drop alive, beating relegation rivals St Pauli 2-0 at home courtesy of goals from Budu Zivzivadze and Eren Dinkci.

Pauli’s loss leaves them in the relegation playoff spot and five points from safety.

Wolfsburg remain in grave danger of relegation after a 0-0 draw at home to Borussia Moenchengladbach. The Wolves, champions in 2009, are a point behind Pauli in the automatic relegation places.

Augsburg drew 1-1 at home to Frankfurt.

In Saturday’s late game, Hamburg host Hoffenheim.