Spurs made a flying start when Brennan Johnson tapped in from Micky Van de Ven's storming run after three minutes.

Tottenham should have added to their lead long before United were reduced to 10 men when captain Fernandes was shown a straight red card on 42 minutes.

Dejan Kulusevski finally doubled the visitors advantage two minutes into the second half before Dominic Solanke rounded off the scoring.

Ten Hag began the season under scrutiny after surviving an internal review at the end of last season.

A shock FA Cup final victory over Manchester City was widely credited with saving the former Ajax coach's job after finishing eighth in the Premier League last season.

A third defeat in United's first six league games of the new campaign leaves the Red Devils down in 11th and time surely running out for their beleaguered boss.

United face daunting trips to Porto in the Europa League and Aston Villa on league duty next weekend before a two-week international break that clubs often use to implement managerial change.

Tottenham boss Ange Postecoglou was himself under pressure just over a week ago.

But Spurs have won four games in 12 days and turned in arguably their best performance of the Australian's reign.

Van de Ven's stunning surge from well inside his own half to the United by-line set the tone as his cross left Johnson a simple task to score for the fourth consecutive game.

Tottenham were without injured captain Son Heung-min and missed the South Korean's clinical finishing as they tried to kill the game off.

Andre Onana saved one-on-ones from James Maddison and Timo Werner, while Johnson smashed another effort off the post.

At the other end, Joshua Zirzkee had United's best chance to equalise when he was denied by a brilliant low save from Guglielmo Vicario.

Any hope of a United fightback was killed off by a moment of madness from their skipper.

Fernandes slipped as he slid into a challenge with Maddison but raised his studs to catch the England international.

Ten Hag responded by sacrificing his only striker in Zirkzee for the much-criticised Casemiro at half-time.

The Brazilian was one of those at fault for the second Tottenham goal.

Solanke outmuscled Casemiro to send Johnson tearing down the right and his deflected cross was cleverly flicked beyond Onana by Kulusevski.

Thereafter the 10 men showed plenty of fight and Casemiro came close to halving United's deficit.

But more calamitous defending allowed Solanke to slide in Tottenham's third from a corner.

Solanke should have rubbed salt into United wounds when Onana saved another one-on-one.

The travelling support taunted Ten Hag with chants of "you're getting sacked in the morning" during the second half.

United's new football leadership team handed the Dutchman an extension to his contract less than three months ago.

How quickly they backtrack on that decision now appears a matter of time.