Solskjaer saw Daniel James score on his debut alongside Marcus Rashford’s brace and Anthony Martial’s goal.
The Norwegian is aiming to get United back into the top four after missing out last year.
He took over from Jose Mourinho in December 2018 before being signed permanently in March.
Solskjaer also saw the club bring in James, Aaron Wan-Bissaka and Harry Maguire – Sunday’s man of the match – over the summer.
The 46-year-old is a hero at the club, scoring the winning goal the 1999 treble in Barcelona.
And he worked in the academy before becoming manager last December.
The United boss has received mixed reviews in his first months at Old Trafford.
But McTominay, who featured against Chelsea, has revealed the impact the manager has as soon as he enters the dressing room.
Speaking on the club’s official YouTube channel, the Scot said: “Ole comes in and it’s ‘boom’.
“Everybody’s 10 feet tall, looking around.
“Ole comes in and it’s ‘boom’ – everybody’s 10 feet tall, looking around”
Scott McTominay on Ole Gunnar Solskjaer
“We think we can play against anybody.
“And I think that comes from the belief instilled in the players and confidence shown.”
It led the United faithful to hail the Norwegian for his impact at Old Trafford.
“In Ole we trust,” one supporter said.
Another commented: “Ole at the wheel.”
While a third simply said: “Ole is going to get it right.”
It comes as McTominay was hailed by fans for his message to James on his debut goal.