Ronaldo returned to the United line-up as a starter after being exiled last week following his refusal to come on as a substitute against Tottenham.
The 37-year-old Portuguese, however, cut a frustrated figure throughout the clash after spurning several chances and being denied by Sheriff goalkeeper Maksym Koval.
Ronaldo also had a goal disallowed for being marginally offside, before he booted the ball into the crowd in an act of frustration.
But Ronaldo got his goal in the 81st minute at the second attempt, hooking in a rebound after his initial header from Bruno Fernandes’ cross was saved by Koval.
“He kept going and the team kept going to put them in the right position,” Ten Hag told reporters.
“He kept going to get himself in the right positions. He didn’t give up, I think that’s what his whole career (has been about), that’s why he is so good and, in the end, he got the reward for it.
“The pressure is always there. Ronaldo knows that and we have to deal with it. All Manchester United players know that. All top scorers need that, every time, the confirmation they can do it.
“Tonight, again, he got his confirmation and he will grow from it. He is hungry. He plays with desire and wants to score goals, as many as possible.
“He has to invest a lot and the team has to invest a lot to put him in the right positions.”
The goal comes with Ronaldo’s future at Old Trafford in doubt, amid growing speculation he could leave in January given last week’s twist. Ronaldo had pushed for an off-season move but nothing materialized.