The red machine have won all eight of their assignments under the crafty veteran tactician, conceding just three goals and plundering 20 in the process. Bayern have their mojo back.
Watch: Heynckes has got Bayern back on track in no time at all
"We're seeing a gradual improvement," Heynckes said modestly, after Bayern went four points clear at the top of the Bundesliga standings with a 3-1 win at Borussia Dortmund prior to the international break. "The intensity is a lot higher in training, but every house needs a firm foundation."
The results of Heynckes' back-to-basics philosophy are marked. Bayern have conceded only one goal in four Bundesliga outings on the 72-year-old’s watch, compared to seven in seven under Ancelotti and interim predecessor Willy Sagnol. Their average possession count is also up from 63 to 89 per cent, while they have seen a marginal improvement in the final third of 2.3 to 2.8 goals scored per game.
Integral to Heynckes' rudimentary approach is Javi Martinez. The 29-year-old was the proverbial glue that bound the defensive and attacking elements of Bayern's 2012/13 treble-winning ensemble, and is thriving once again in his preferred role of midfield stabiliser after spending the last four seasons moonlighting as a centre-back.
"He's not just a Basque – he's robust, a real fighter," Heynckes said of 18-time Spain international Martinez. "You have to put in a lot more leg work in midfield compared to in central defence, and he does it brilliantly. Since he's been playing in midfield we've improved our stability and the quality of our defensive work."
Watch: Javi Martinez - Bayern's midfield rock
Martinez's ability to read and unceremoniously break up opposition attacks has also returned a degree of unpredictability to Bayern's forward play. Although possession-based football remains a key facet of their game, they can be equally as, if not more, devastating on the counter. Similarly, over-committing men in the final third is less of a concern, with the Spanish shock absorber sitting deep, patrolling the back four.
"Javi's incredibly important," explained Bayern wide man Arjen Robben. "He played more as a centre-back last season and now he's back in defensive midfield, playing very well when we don't have the ball. He's so important in that defensive midfield role, just as he was during our very successful previous spell with Heynckes."
Bayern's about-turn in fortunes, however, is not just down to one man and his most trusted midfield enforcer. There is continuity in the side, and the squad as a whole appear to be enjoying their football again. Post-match appraisals with undertones of dressing room unrest are ancient history.
"The discipline, the clear structure [Jupp] brings – they're all things that are doing the lads the power of good,” said Bayern defender Mats Hummels. "When he came in, he spoke to everyone at length. It's great for players if they know exactly what he does and doesn't want to see."
Five weeks on, buoyed by eight straight wins - including back-to-back Bundesliga triumphs against nearest challengers RB Leipzig and Dortmund – Don Jupp must now be asking for more of the same. Normal service, by Bayern's standards, has been resumed.