Moenchengladbach's Matthias Ginter (right) celebrates after scoring against Bayern Munich on Saturday. Photo: Ronald Wittek/EPA

Bundesliga leaders Bayern Munich suffered their first defeat since Jupp Heynckes returned as head coach when they fell to a 2-1 loss at Borussia Moenchengladbach on Saturday.

Before losing at Gladbach, Bayern had won all nine games since Heynckes, 72, took over for his fourth stint at the club in October in the wake of Carlo Ancelotti’s dismissal.

It was an unhappy return for Heynckes to Moenchengladbach, where he spent most of his playing career and where his family home is. 

“We didn’t invest enough in the first half,” admitted Heynckes.

“We played too slowly and didn’t find our rhythm, so we have to put the defeat down to the first half.

“We were better after the break, but Gladbach were clever in defence.”

Gladbach suffered an early setback when Germany midfielder Christoph Kramer was sent off on a stretcher following a nasty clash of heads with teammate Jannik Vestergaard.

A first-half penalty converted by Thorgan Hazard, after a Niklas Suele handball, put Gladbach ahead.

They went into the break 2-0 up at Borussia Park when Lars Stindl’s pass was converted by Matthias Ginter to the delight of the home fans.

Heynckes responded by bringing on Austrian midfielder Marco Friedl, 19, for his Bundesliga debut.

He came on for the second period in place of James Rodriguez, who suffered a suspected concussion in a clash of heads with Kramer’s replacement Tony Jantschke.

“He (Rodriguez) didn’t know what the score was at halftime, so I assume it was a concussion, but we have to wait for a proper diagnosis,” said Heynckes.

Bayern managed to pull a goal back when Chile international Arturo Vidal fired in a long-range shot on 74 minutes which Yann Sommer got a glove to, but couldn’t prevent from rolling into the net.

With time almost up, late replacement striker Josip Drmic fired wide as Gladbach held on for the win.

It is only Bayern’s second league defeat this season, having also lost 2-0 at Hoffenheim in September, but they still hold a three-point lead at the top of the table.

Gladbach move up to fourth, level on 24 points with third-placed Schalke, who came from four-goals down to draw at 10-man Dortmund as a dramatic Ruhr derby finished 4-4.