Ole Gunnar Solskjaer thought his side should have been more clinical after they disposed of Sheffield United on Wednesday evening.
United won 3-0 and deservedly so as Paul Pogba started his first game since September.
The mercury was at 30 degrees Celsius when play got under way at Old Trafford and the hosts made a scorching start.
Martial directing home at the near post with just seven minutes on the clock for the first of his maiden hat-trick for United.
It was more than enough for Solskjaer’s in-form side coast to victory against their fellow European hopefuls.
Having been roared to derby victory against Manchester City in their last home match, giant stadium wraps replaced supporters as an empty Old Trafford hosted competitive football for the first time in 108 days.
Manchester United dealt with the unusual backdrop superbly and secured their first victory since football resumed amid the coronavirus pandemic, with Martial’s treble sealing a straight forward win.
It was the Red Devils’ first Premier League hat-trick since Robin Van Persie hit three in 2013, extending their unbeaten run to 13 matches and boosting their top-four hopes on a night that had initially been pencilled in for a neutral venue.
After the game, Solskjaer told reporters that United can still get better in front of goal – and he is also dreaming of a higher finish than fourth place.
“Very pleased with the performance but there is still more to come,” said Solskjaer.
“We could and should have scored more goals to put the game to bed before half-time. It is always worrying going into half-time knowing you should have scored goals.
“The way we controlled the game, pressed and stopped them playing, [I’m] very happy with it. Still more to come and we shouldn’t be 100 per cent happy with it.
“I have never said fourth is our aim. We would like third and there are two cups for us.”
Solskjaer had words of praise for the hat-trick hero, Martial. And it appeared the treble was no mistake, as the manager revealed two of the goals came from training routines.
“Very happy for Anthony when you get a hat-trick. It’s just unfortunate he didn’t celebrate with our fans.
“I think the first goal – I think that’s a vital goal as well today – but the way he turned and got himself into a position to score from Marcus’ cross, I was very pleased with that one.
“He’s getting more and more into those positions. He nearly got a goal against Tottenham as well, great turn and finish and great save by [Hugo] Lloris. Anthony’s in good form.
“The third goal was a great goal. But for me the first and the second were better. He’s in the box, ready to go. We have worked on that, getting in the box in that situation more often.
“At the near post he showed composure and I think, as I said, the first goal was vital the way he turns and gets himself into a position to score from Marcus’s cross; very pleased with that.”