Coventry boss Mark Robins said securing Sky Bet Championship safety was the best achievement of his managerial career.
The Sky Blues suffered a 1-0 defeat to Preston at St Andrew's, with Alan Browne's penalty separating the sides in a close encounter.
But Derby's defeat to Birmingham means the Sky Blues are mathematically safe, and Robins said: "It's absolutely huge. This is the biggest achievement in my managerial career.
"It's gone so much beyond even winning League One last season.
"Credit to the players because they have put in an unbelievable amount of effort.
"We've had to play through a pandemic and, of course, it's been so tough. It's been unprecedented and hopefully we never have to go through it again.
"It has been horrific for everybody and then to compete in sport on the back of that has been a miracle."
Robins is now relishing the chance to play in front of fans at the Ricoh Arena next season.
"We haven't been able to experience that in the Championship with the fans," he said. "To get the level of performance we have without supporters is amazing. You miss them so much.
"It's a false game without them, so it will be a great experience next year with them."
Meanwhile, Frankie McAvoy hinted he would like the Preston job on a permanent basis after watching his side take all three points.
"The task I was given with eight games to go was to win as many games as we could and I think we've done well," he said.
"We've had three clean sheets in a row now and credit to the lads, they have worked their socks off and I cannot thank them enough.
"At the end of the day, they are the boys who do it on the pitch.
"We can guide them and support them but they are the ones who go out there.
"We'll see what happens now. Let's see how we finish.
"We will take each game as it comes and we will try to get as many points as we can.
"From my point of view, I will just keep doing what I'm doing.
"I was given an opportunity for eight games and I said I'd give it my best shot.
"I like the job and I'm loving it at Preston but that decision is for others. We'll see what happens at the end of the season."
On the win over Coventry, he added: "We knew it would be a tough game. I felt we were better in the second half and changed a few things.
"I felt we might have had a penalty before and you have to make sure it doesn't affect you when the decision doesn't go for you.
"We got the penalty and it was a good win for us.
"As I say, I'm delighted for the lads. Our task is to find the best formation to win games but it's the players who have made the difference."