LONDON • Ole Gunnar Solskjaer knows a thing or two about impact substitutions, but even Manchester United's former supersub extraordinaire must have been pleasantly surprised to see Romelu Lukaku step off the bench and score within 38 seconds on Wednesday.

Until then, Solskjaer had seemed outwitted by Rafael Benitez's contain-and-counter tactics. But, by the end of a bitterly cold night, Marcus Rashford had added a second to seal a 2-0 win over Newcastle.

It makes the Norwegian the first United manager since Matt Busby in 1946 to win his opening four games. He acknowledged it would be "hard" for him to relinquish the role and return to his "day job" at Molde in Norway in May.

"Of course I won't want to leave," the 45-year-old said, semi-teasingly. "I don't want to."

His smile suggested he knows he will almost certainly have to, although much more of this and all bets will be off.

If United's flight to the warmth of Dubai tomorrow for a mid-season training break should be a happy one, Newcastle remain far too close to the relegation zone for comfort.

Things certainly appeared to have changed since the last time Solskjaer patrolled the away technical area at the St James' Park in 2014.

Back then, Alan Pardew was in charge of a home team whose 3-0 win confirmed Cardiff's relegation from the Premier League.

Not that Jose Mourinho's interim successor could afford to relax, even with a new-found sense of creative liberation, that was cowed and cramped by his predecessor, leading to 12 goals before the game.

Indeed, United could easily have conceded early when Phil Jones' poor back pass played Salomon Rondon onside. In the end, the defender recovered superbly to rescue the situation.

"Finally we kept a clean sheet," Solskjaer told Sky Sports. "A very professional performance. We didn't hit the heights that we can do, but we were in control, kept plugging away and got the goals."

At the other end, Paul Pogba, the chief beneficiary of the regime change with four goals and three assists, regularly advanced down the inside-left channel with destructive intent but the final ball was not quite coming off against the hosts' five-man defence.

Yet this was also very much a collective effort, a masterclass in the art of assiduous closing down. With less than half an hour left, the time had come to liberate Lukaku and Alexis Sanchez from the bench.

Lukaku scored with his first touch when Slovakia goalkeeper Martin Dubravka uncharacteristically spilled Rashford's dipping 25m free kick. The forward reacted with alacrity, responding faster than Jamaal Lascelles to drive the rebound home from six yards.

Said Solskjaer: "A good first touch from a sub. When you see big Romelu Lukaku running towards you, as a 'keeper you might take your hands away."

All that remained was for an unmarked Rashford to slide a shot through Dubravka's legs at the end of a move he had started. It involved Lukaku cueing up Sanchez, who marked his return from hamstring trouble with an assist that rekindled hopes of a top-four spot.

"Marcus has a great hit," said Solskjaer. "He must have been watching Cristiano (Ronaldo) practising. Without hitting the heights, it was a very professional performance."

THE GUARDIAN, AGENCE FRANCE-PRESSE