This was dangerous territory for Jose Mourinho '“ and Newcastle

It’s said 2-0 is the worst lead in football.

And so it turned out for Rafa Benitez’s side at Old Trafford on Saturday, where Manchester United came from behind to win 3-2.

Newcastle, however, should have had a better lead when referee Anthony Taylor blew the half-time whistle.

That whistle was greeted by boos from the home fans.

The 3,000 travelling fans tucked into one corner of Old Trafford won’t have seen a more dominant first-half performance from their team.

They’d seen an exhilarating 45 minutes from Newcastle, again watched by owner Mike Ashley.

Benitez had been cautious away to Manchester City last month. There was no caution or five-man defence on this return visit to the city. Benitez sensed an opportunity, and they went for it.

Kenedy’s fourth-minute goal stunned the home crowd. Ayoze Perez broke forward and squeezed a ball through a game in Man United’s defence for Kenedy to run on to. The winger cut inside Ashley Young and tucked the ball into the far corner of the net with his favoured left foot.

Mourinho’s expression on the touchline told its own story.

It got better in the 10th minute. Jonjo Shelvey delivered the ball into the box for Yoshinori Muto, making his full Premier League debut.

Muto controlled the ball with his back to goal, turned and shot past David De Gea.

Shelvey tested De Gea with another shot before Mourinho withdrew Bailly in the 19th minute.

Marcus Rashford missed a header from a Romelu Lukaku cross at the other end of the pitch, but the momentum was with Newcastle, who should have had a penalty when Young diverted a Jonjo Shelvey free-kick out for a corner.

Taylor – who was looking elsewhere – awarded a goal kick to Man United, and not a penalty to the visitors.

Mourinho couldn’t get to the home dressing room quick enough at the break, and he replaced makeshift defender Scott McTominay for the second half.

Newcastle saw much less of the ball after the interval, though Kenedy, later forced off after Paul Pogba clipped him, shot over with one chance.

Mata got Man United back into the game in the 70th minute. The midfielder beat Martin Dubravka with a free-kick, conceded by Mohamed Diame, struck from the edge of the box.

Dubravka superbly denied Marouane Fellaini and Chris Smalling as Mourinho’s side pressed for an equaliser, but he couldn’t stop a fine shot from Martial, who equalised in the 76th minute after exchanging passes with Pogba.

It just seemed a matter of time before Man United would get the winner.

Minute by minute, the clock at the Stretford End slowly ticked down, and Alexis Sanchez, brought on midway through the half, eventually netted in the 90th minute.

It had been an agonising 20 minutes.

Dubravka had been outstanding in the visiting goal, but it wasn’t enough.

Man United just had too much of everything. They played with pace, power and purpose. It was just too much in that last period.

The result left the winless club, which has played five of last season’s top six, 19th in the table.

It was a gut-wrenching defeat, yet there were more positives than negatives to come from it.

Newcastle had played their best 45 minutes of the season so far.

If ever there was a good defeat, this was it. The performance, at the very least, will have given the players belief going into a more winnable run of games. They can’t come soon enough.