There's life in the old dog yet. Just four days after a supine performance against Bournemouth which seemed like the nadir of his time at Tottenham, Jose Mourinho bounced back to engineer his biggest victory with the club.
The most satisfying thing for the Spurs manager will be that he did it his way. As his side fell back in the second half, ceding possession and territory to their local rivals, you felt Mourinho was making a sizeable rod for his own back.
It seemed an admission of inferiority guaranteed to boost claims that he is a man out of time dragging Spurs down a negative dead end.
But with the half wearing on and Arsenal's ponderous build-up stalling, Spurs started to hit them on the break. In the 70th minute Harry Kane rounded Shkodran Mustafi and cut the ball back for Son Heung-min who seemed certain to score before 'keeper Emiliano Martinez swiped the ball off his toe.
Ten minutes later Kane looked set for a goal after Lucas Moura picked him out, but Martinez rescued Arsenal again. The reprieve was brief, Toby Alderweireld rising to head home Son's subsequent corner.
At the final whistle Mourinho gestured triumphantly to the absent crowd. The end had justified the means.
This was the kind of heist he pulled off regularly in his heyday, most notably when Chelsea beat Liverpool 2-0 with Brendan Rodgers' Reds apparently poised to win the title.
That it's his most significant win in a couple of seasons shows how far the man's stock has fallen. This time four years ago, as the newly-appointed Manchester United manager, he was preparing to challenge Pep Guardiola for the Premier League title. Now he's fighting it out with the City boss's former assistant for a Europa League place.
But this performance shows that Mourinho is not in freefall. He's still smart enough to make a neophyte like Mikel Arteta look very callow indeed.
Unlike Mourinho, Arteta has enhanced his reputation since taking charge in north London. Arsenal went into this one with six wins in their last nine league games and just two defeats in their last 14. Yet despite having 63 per cent of possession they were outfoxed by Mourinho's rope-a-dope strategy and looked ragged by the end.
For all the negativity surrounding Mourinho, Arteta will have more work to do than the Spurs manager during the truncated off season.
The moments leading up to the home team's first goal exemplified the kind of flakiness which cost Unai Emery his job and makes his successor's unnecessarily difficult.
Sead Kolasinac was the main culprit as his misplaced pass to David Luiz gave Son a run on goal. Yet the Brazilian's reaction was flatfooted in the extreme. He looked less like a pursuing defender than a guard of honour escorting Son forward to beat Martinez.
That equaliser came just three minutes after Alexandre Lacazette had given Arsenal the lead with a marvellous drive and perhaps things would have been different had the Gunners stayed in front for longer.
Yet Spurs seemed the more substantial team. Arteta's outfit have too many of the kind of players - Luiz, Kolasinac, Mustafi and Granit Xhaka - who get managers fired.
Arsenal's new boss has been praised for the firm hand he's taken with Mesut Ozil and Matteo Guendouzi. But a look at yesterday's line-up suggested that dispensing entirely with the subtlety of the former and the energy of the latter might be a little self-indulgent. The jury is still out on Arteta.
Spurs' win has the symbolic significance that derby victories always do and should lessen the pressure on Mourinho. Despite claims that Kane is ill-served by the manager's new system, the striker had three one-on-ones against Martinez.
Success in any one of them would have made him the all-time top scorer in this fixture, yet it was not to be.
Kane's imprecise finishes were in stark contrast to the delicacy with which Son executed his chip over Martinez. In a choppy season for his side, the South Korean has been outstanding.
Mourinho will hope to hang on to both of them but Tanguy Ndombele's troubled time at White Hart Lane seems to have run its course with Barcelona apparently keen to acquire him and Ryan Sessegnon through player swap.
It's ironic that after all the criticism of Daniel Levy's previous parsimony in the transfer market, Spurs' two big close-season buys have flopped miserably.
Ivan Rakitic and Philippe Coutinho are among the players Barcelona want to offload this summer and the arrival of either would surely be popular with Spurs fans. Yet the sight of Harry Winks reduced to chasing and committing petty fouls yesterday illustrated the often parlous situation of creative players under Mourinho.
Someone in the Rakitic or Coutinho mould could find his face doesn't fit at Spurs. Mourinho might be happier recycling Marouane Fellaini.
He's not going to change his ways now. The Spurs manager continues to possess football's most impregnable ego. Witness his comparison of himself with Jurgen Klopp in the aftermath of the Bournemouth debacle. This victory showed that rumours of his irrelevance to the modern game have been greatly exaggerated.
Mourinho might not be The Special One anymore. But he hasn't become The Knackered One just yet.