"It is tough still counting goals for Ronaldo because every week seems like a new record," Bruno Fernandes told BT Sport.
"I am really happy because he has been working hard to get this goal. Today he got the goal and the win and that is the most important for him, that the team won."
Everton started in strong fashion and took the lead within five minutes as Iwobi curled an effort past David de Gea from outside the box.
United, though, provided a swift response and levelled the game just 10 minutes later as Antony was found in behind by Anthony Martial. The Brazilian shifted onto his favoured left foot and fired past Jordan Pickford to score his third goal in as many matches for United since signing from Ajax.
Martial, the provider, was forced off after struggling with an injury just before the half-hour mark and was replaced by Ronaldo.
And it was the substitute Ronaldo who gave United the lead, scoring his 700th club goal a minute before the end of the first half.
The Portuguese striker burst down the left flank and showed his goalscoring pedigree with a clinical low, left-footed strike past Pickford.
Both sides traded spells of pressure in the second half, but neither had the decisive moment of quality until it seemed Marcus Rashford sealed victory for United nine minutes from time.
Rashford beat Iwobi and James Tarkowski out wide before taking the ball past Pickford and firing into a vacated net -- but the effort was ruled out following a VAR check for an adjudged handball.
"It was disappointing because we had been moving in the right direction," Everton manager Frank Lampard told BT Sport.
"United had good possession and moved the ball well. There's a lot I can reflect on in the game but when you look at it in the cold light of day it was two of our mistakes that led to goals."
United's victory moved them up to fifth in the Premier League table.