I will not give up – Borussia Dotmund's Bosz defiant after Ruhr derby collapse
Goals from Pierre-Emerick Aubameyang, Mario Gotze and Raphael Guerreiro – combined with an own goal from Benjamin Stambouli – had put Bosz's side well in control by the 25th minute of Saturday's Bundesliga encounter at Signal Iduna Park.
But two goals in the space of four minutes hauled Schalke back into proceedings after the break, before Aubameyang's dismissal for a second bookable offence put Dortmund on the back foot.
And Schalke's numerical advantage eventually proved too much as Daniel Caligiuri cut the deficit to one and Naldo headed home an equaliser in stoppage time to cast further doubt over Bosz's future, with Dortmund now winless in their last six games across all competitions.
"We will have to work hard, I did that all my life," said Bosz, who last oversaw a top-flight win in September.
"That's the kind of player I was, I never gave up, and as a coach I will not give up either.
"I will cheer up the players, nobody needs to cheer me up, I'll do that myself. I did that all my life and I will do the same now.
"It was a crazy game. If you were there, you cannot believe it, that is, I cannot believe it."
25 - It was the second fastest 4-0 lead for @BVB against Schalke (after 25 minutes) - in september 1964 Dortmund led 4-0 vs. Schalke after 23 minutes (final score 6-2). Spectacle. #BVBS04
— OptaFranz (@OptaFranz) November 25, 2017
Aubameyang was suspended by Dortmund for internal reasons last time out in the league, but marked his return to domestic action with a goal 12 minutes in, having also netted in the Champions League loss to Tottenham in midweek.
Stambouli's own goal quickly followed before Aubameyang turned provider with an inch-perfect cross into Gotze – Guerreiro's volley capping Dortmund's scintillating first-half display.
With Naldo having already seen a goal ruled out for offside, and Aubameyang squandering a golden chance at the other end, Guido Burgstaller pulled one back for Schalke just after the hour.
Amine Harit made things interesting four minutes later, but it was not until Aubameyang's red card that Schalke really took control – Caligiuri curling home before Naldo levelled in stoppage time, and Bosz offered no excuses for his side's dismal defending.
"We started well and if you are leading 4-0 at half-time you can never draw 4-4," added the Dutchman.
"I believe that happened because in the second half we didn't play clear football. The first half we tried to play football, we did it very well.
"We didn't take advantage and when you look at the way we conceded the goals, that just can't happen on our level. Unfortunately it did happen."