Coventry City sealed the Championship title after thrashing Portsmouth 5-1 at home on Tuesday.
Frank Lampard's side, who confirmed their promotion to the Premier League on Friday, will now go up as champions of England's second tier.
United States striker Haji Wright, the club's top scorer this season, broke the deadlock at the CBS Arena on Tuesday with his 17th league goal of the campaign in the 12th minute.
Ephron Mason-Clark added a brace in the second half, either side of an own goal from Portsmouth's Regan Poole, to make sure of the three points and the title before Kaine Kesler Hayden netted a fifth in stoppage time.
Adrian Segecic scored a consolation for 19th-placed Portsmouth.
"It was just a great night," Lampard said in his post-match news conference. "It was so nice because we had the jeopardy of Friday night, which in a weird way was great the way we did it.
"That was amazing in its own right, this is amazing in its own right. This is what I really, really wanted because we led the table for so long and pushed on this second half of the season as it's gone on.
"That takes a really strong unit and a strong group and they've shown that."
The win takes Coventry to 89 points for the season and an unassailable lead with two games remaining.
The Sky Blues will return to the Premier League for the first time in 25 years after relegation at the end of the 2000-01 season.
Despite a trophy-laded career as a player and two spells as manager of Chelsea, Lampard put this season's achievements high on his list of accomplishments.
"It's right at the top of my career," he said. "I said it after Blackburn and to seal the title in the manner that we did, the way the team played from minute one, how we stepped it up in the second half.
"We've had a lot of these performances at the CBS [Arena] this year, this team has been so consistent. The last few weeks have been challenging in a way because of the pressure, because we're not used to this and we've got the results we needed recently to get us promoted.
"When you get this close, to go and do it with two games to spare is incredible, because this league gets harder.
"All the teams here give you different challenges in this league and these players have got 27 wins, it's amazing what they've done."
PA contributed to this report.