Beads of sweat glistened on his bare head, the London afternoon sun beating down on the Dutchman as Brentford dismantled United, tearing them apart with glee in the first half. It was as bad as anything produced in the dogged era of David Moyes, Louis van Gaal, José Mourinho and Ole Gunnar Solskjær, and far worse than any performance under Ralf Rangnick, his much-mocked immediate predecessor. But it was still a familiar story. The mistakes of previous seasons are several leagues away from being rectified and although fans can clearly look for outs and fresh blood, two of the Ten Hag’s additions in Lisandro Martínez and Christian Eriksen played a full part in the disaster. That United’s problems run even deeper was reflected by continued protests against Glazer’s ownership of the away goal, although the absent Florida billionaires have not been on the pitch during their two woeful starts to this Premier League season League. Nor did they choose a group that acted as indifferent satellites of each other. “I asked them to play with faith and take responsibility, that’s not what they did,” Ten Haag said afterwards. “I have to give them credit, but they have to give it themselves.” There seems to be little unity to go around, even if there was plenty of responsibility. A snarling Cristiano Ronaldo was more than happy to level it and put Ten Haag and the away fans out at full-time. David de Gea after conceding the opening goal. Photo: Mark Leech/Offside/Getty Images At least there wouldn’t be a repeat of the big man’s face on the bench, as seen last week against Brighton. Instead, Scott McTominay was the only player to be ruled out of a disappointing opening weekend in what now looks like happy, optimistic times. Alongside McTominay’s former partner in crime Fred, Eriksen played the deep, central role from which he helped propel Brentford to safety last season, with much less success. A vocal minority of home fans were unrelenting in their choice of Manchester over west London, his early touches booed and hearty reminders of the scoreline. Josh Dasilva’s goal had rescued a point at Leicester last Sunday and got the nod, a team selection from Thomas Frank that is paying off in a way the Ten Hag can only dream of. He must also envy their energy and application. Brentford played their usual athletic game, pressing hard, making full use of the set-pieces, of which United’s persistent free-kick offered many in utter desperation. “We knew the high press would affect them,” said standout Ivan Toney. “It was clear that if you work hard, you will get results.” Mathias Jensen, dominant in the midfield, said: “It felt like we were on top of everything.” “We looked at what Brighton did well against them,” Frank said. “We knew we had that weapon.” Da Silva’s long opening came through a combination of aggression, submission and incompetence. Jensen easily robbed Ronaldo and De Gea made a not-so-uncharacteristic mistake. For all his tactical brilliance, the Spaniard is prone to clangers. The ball went over the line, he buried his head in the turf. “I just take my responsibility today,” said De Gea, accepting responsibility. “I think I cost my team three points. It was a poor performance from me.” Start your evenings with the Guardian’s view of the world of football Privacy Notice: Newsletters may contain information about charities, online advertising and content sponsored by external parties. For more information, see our Privacy Policy. We use Google reCaptcha to protect our website and Google’s Privacy Policy and Terms of Service apply. Bryan Mbeumo and Brentford celebrate their win. Photo: Mark Leech/Offside/Getty Images De Gea was not alone in his ineptitude. Far from it. Harry Maguire was only saved from a red card when he brought down Ivan Toney because Martinez was at the scene of the crime. And as United tried awkwardly to play the ball out of bounds, Eriksen faced trouble from Martinez. Jensen stole second. Just 18 minutes into the game and Ronaldo was barking at his team-mates while Brentford fans predicted Ten Haag would be sacked in the morning. Thirteen minutes later, Ben Mee bent over the back post to score after Toney won a corner. The next was even simpler, Jensen robbing Jadon Sancho in the box, releasing Toney, who played in Bryan Mbeumo as Brentford crossed unchecked. The Ten Hag’s half-time reaction, their attempt to shake off the shell shock, was to take off the unfortunate Martínez and Luke Shaw and swap McTominay for Fred. United looked a little more settled, if still fragile, their attack still unlucky. United were at least enjoying some ground. Ronaldo’s first chances both came from Diogo Dalot’s crosses and he beat the turf in anger after heading both. He soon found himself falling deep as he tried to do something, anything, maybe save his own night with a goal. Eriksen forced the first save of the game from Brentford goalkeeper David Raya with a weak header as the home side sat back on their advantage, able to savor the occasion. Jensen, Mbeumo and Dasilva left the pitch to a standing ovation on a famous Brentford day, a first defeat for United since 1938 that will live long in the memory. The celebrations afterwards were tumultuous and long. For Ten Haag, and all those who hope that Manchester United can one day be revived, this will remain a fever nightmare, a new but familiar low.