Sheffield United were promoted to the Premier League after a 12-year absence on Saturday.
The Yorkshire club secured the second automatic promotion place after fourth-placed Leeds United were held to a 1-1 draw by champions Reading.
United, who have languished in the second tier of English football since their relegation from the top flight in the 1993-94 season, won 1-0 at Cardiff City on Friday to move to 85 points with three games to play.
"It's a marvellous feeling. It's the greatest achievement in my career as a manager because there are so many big clubs below us and it's such a hard league," manager Neil Warnock, born in Sheffield and a lifelong fan of the Blades, told Sky Sports.
The Bramall Lane side made a flying start to the season, winning 10 of their first 11 matches but it was Reading who proved to be the division's outstanding side, running away with the title which they secured at the start of April.
United began to falter in February and March, giving hope to Leeds and Watford, before they recovered their composure.
Warnock, who took charge in December 1999, believes his side can match Wigan Athletic next season and stay in the top flight against the odds. Unfashionable Wigan have enjoyed a fine debut season in the Premier League and sit in mid-table.
"I think we have a good nucleus of youngsters. Yes, we will have to improve our squad but I think the Premier League will enjoy having us," he said.
"We will be a little bit of fresh air and I don't think we have anything to fear, it will be nice to pit our wits against the big boys."
Asked to name which sides in particular, Warnock joked: "My wife would like to meet (Chelsea manager Jose) Mourinho for obvious reasons ... the good-looking swine."
Rob Hulse fired Leeds in front at Elland Road before Stephen Hunt's goal five minutes from time earned Reading a draw to take Steve Coppell's side on to 99 points.
Leeds will contest the playoffs along with Watford, Preston North End and Crystal Palace.
