Bayern Munich 1-2 Eintracht Frankfurt, Allianz Arena
(Goretzka 29' – Hinteregger 32', Kostic 83')

The Oliver Glasner era has lift-off. At the seventh time of asking, Eintracht Frankfurt finally won under their new coach – and they did it at the home of the Rekordmeister Bayern Munich.

The Allianz Arena has been a hostile environment for Frankfurt in recent times; the Eagles traveled to Munich having endured 15 defeats in their last 16 league games there. A single point is all they had to show in 20 years of visits to Bavaria – but on Sunday night the slate was wiped clean.

Such is Bayern's dominance of the Bundesliga that any defeat they suffer is celebrated as a victory for the league, and this result will certainly be a boost for the peloton led by Bayer Leverkusen and Borussia Dortmund.

The latter would have found themselves on the wrong side of a four-point gap had Bayern picked up an expected three points. Instead, that lead is kept to a single point.

Trapp: 'Belief — and a little luck — was key'

Victory was sealed with a pinpoint drive by Filip Kostic, a player who was agitating for a move away from Frankfurt in the summer. The Serbian's fine winner was a death knell for Bayern and a reminder of the quality he possesses. Those qualities will have to be harnessed more regularly if Frankfurt are to build on this statement victory.

However, as clinical as Frankfurt were going forward, this victory would not have been possible without goalkeeper Kevin Trapp, whose performance was nothing short of heroic. A series of fine saves in both halves denied Bayern time and time again – he made 11 stops in total and at least three of them can be filed under the category of world class.

His stops from Leroy Sane, Robert Lewandowski and Serge Gnabry were inspired and his 91st minute one-handed denial of a Leon Goretzka piledriver was as impressive as it was crucial.

"Hats off to the team," a beaming Trapp told DAZN at full-time. "It was a lot of work today but we did really well, and there was a little luck involved too. Not many people believed that we would get anything here."

Humble in victory, Trapp also probably felt like he had something to prove. Just days after being left out of Hansi Flick's Germany squad in favor of Bernd Leno, who is currently being kept out of the Arsenal team, Trapp couldn't have reminded the watching Bundestrainer more emphatically of his qualities.

Trapp, so often overlooked in the conversation of Germany's goalkeepers, provided a perfect repost to his critics. And in delivering a near-flawless performance, he helped deliver Frankfurt's first win of the season after an improbable run of four straight 1-1 draws, plus another one in the Europa League.

Defeat exposes Bayern flaws

While the game ebbed and flowed into a compelling contest for the neutral, it also exposed the faultlines in Bayern's approach.

Central defender Dayot Upamecano looked shaky at times as he continues to adjust to his new team, and Alphonso Davies continues to be more of a weakness for Bayern when he starts as a classic left-back, rather than as a wing-back advancing further up the field.

Neither was directly to blame for the defeat but victory would only have papered over the cracks, even if they are issues that Nagelsmann will feel are not terminal. Bayern's Thomas Müller was intolerant of any notion that the defeat wasn't so bad.

"We are disappointed, angry, annoyed. I don't know which word is best," Müller said at full time. "If we make it 2-1, it can end 3-1 or 4-1. But this is not a game that we should lose under any circumstances."

The upside for Bayern is that Sane continues to edge towards something like his best, and Gnabry looks sharper, even if his missed chance to make it 2-0 when he hit the post, would probably have made for a different outcome.

Bayern remain a balanced and hungry team under Nagelsmann and, when they click into gear, an almost unstoppable force. Even here, they suffocated Frankfurt for long periods. 

However, on this occasion, they met a Frankfurt team who have an ice-cold finisher in Kostic and a goalkeeper in Trapp who couldn't have chosen a better time to produce a virtuoso performance at the home of the serial champions.