Smalling was put in a hard position by Paul pogba in the second half after the Frenchman attempted a ridiculously flamboyant chip in the centre of the park which only achieved setting up the visitors with a free run on goal, which Richarilson made the most of.
Everton couldn't find an equaliser in the end and the Red Devils looked relieved when the full-time whistle finally blew after 96 minutes.
Pogba was involved in both United goals on Sunday, later teeing up Anthony Martial to hit what ultimately proved the victor. He took an incredible 10 second run up before having his penalty saved brilliantly by Jordan Pickford, with the rebound falling straight at his feet for him to put away.
"But in these matches where you don't score, where you don't assist, where your creation is not at the high level, but you have a certain balance in your performance, that's where I think he is going well".
The Spaniard did a good job at the start of the game, but his passing and movement were off in the last 20 minutes or so. Young was slightly fortunate not to see yellow for a challenge that felled Lucas Digne on 35 minutes.
United were somewhat lucky to get the penalty to begin with. Sigurdsson stepped up and smashed the penalty into the top-corner, halving the deficit.
A United free kick following a foul by Zouma on Rashford led to a cross from the left by Martial that saw a Mata header comfortably dealt with by Pickford.
United, meanwhile, held a minute's silence before kick-off, in joint memory of Remembrance Sunday and the helicopter crash on Saturday evening involving the aircraft belonging to Leicester City owner Vichai Srivaddhanaprabha. 'At the moment he is playing very well. Everton, who drop to ninth, host Brighton.
Ander Herrera, Paul Pogba, Anthony Martial, Ashley Young, Andreas Pereira and Fred also met the young players, whose predicament attracted worldwide attention last summer. Let off for the Red Devils.
Pogba baby-stepped his way up to the ball in near slow-motion, taking an incredible 26 steps before making contact with the ball... On Sunday afternoon's showing, there could be some validity to this. The Everton midfielder avoided a booking shortly after earning his first, but his team-mates argued that he got the ball and it should not have been a penalty at all.
Silva's decision was to stick with the latter and it did not pay off.
27' - GOAL! Man United 1-0 Everton. Everton's manager may well consider starting Tosun against Brighton next week.
There were some decent performances at Old Trafford, and here are the player ratings from the game. The Icelandic midfielder provided a constant and direct threat.