Ole Gunnar Solskjaer admitted Manchester United "didn't play a great game" as they battled to a 1-0 victory over Leicester City at Old Trafford.
Marcus Rashford's eighth-minute penalty settled a contest that was not always high on quality, as Leicester's unbeaten start to the season came to an end.
The visitors enjoyed 58 per cent of the possession but did not create much by way of meaningful opportunities, although David de Gea did make good first-half saves from James Maddison and Ben Chilwell.
Rashford, who missed a penalty in the loss to Crystal Palace last month, took his spot-kick well before United opted to sit deeper and threaten on the counter-attack.
Solskjaer was not overly impressed with the performance in the final hour, but he was delighted with a clean sheet and the way in which his players worked.
"Three points, clean sheet, the camaraderie and togetherness, the work rate," he said when asked what pleased him most about the win.
"Let's not kid ourselves - we didn't play a great game. The first 20, 25 minutes were fantastic but then we gradually lost control of it. Towards the end, I felt we were in control again.
"It was probably the first time this season apart from spells against Chelsea that we've had to defend as a team for longer periods. I was pleased to get a clean sheet; David got a couple of good saves.
"This stadium, they love effort and attitude and energy. For the penalty, Andreas [Pereira] wins a tackle inside the box, Marcus sprints and just gets in front of him [Caglar Soyuncu] - the fans love that.
"People are talking about our lack of clean sheets. We've had Chelsea and Leicester here, two good teams who are going for the top four, and we've kept clean sheets against them."
Harry Maguire was booed by the travelling support even before kick-off but produced a fine display at the heart of the defence to keep his old team-mates at bay.
"It didn't look like he missed them too much!" Solskjaer said. "He did really well. He stuck his head in and he was so calm on the ball for us and we needed that in the second half."
On Rashford's penalty, Solskjaer added: "He's been practicing. Everyone can miss a penalty - I've seen [Diego] Maradona, I've seen [Lionel] Messi, all the best ones miss penalties. He was calm and just wanted it to come his way."