Russell Martin insisted Southampton will not shift styles on their return to the Premier League after victory in the Championship playoff final and vowed to prove any sceptics wrong. Saints sealed an instant return to the top flight after Adam Armstrong’s first-half strike was sufficient to beat Leeds and ­Martin said he plans to stick with his ­possession-based philosophy.

Related: Southampton promoted to Premier League by beating Leeds in playoff final

Martin, who captained Norwich to the Premier League via the playoff final nine years ago, has developed his style since taking his first steps into coaching in League One with MK Dons. He was tasked with earning promotion after leaving ­Swansea to take charge at Southampton last ­summer and revealed his first ­promotion as a manager was “the best feeling I’ve had in football”.

“For me, if you win this way, it’s the best way,” he said. “There’s no right or wrong way but it’s what I believe in, it’s what we believe in. And we finally won something doing it … so I guess it will be some form of validation for some people. I love what we do and I’m not going to change and I’m sure it will start – it probably already has – that we won’t play this way in the Premier League and all of that stuff, the scrutiny and the intensity that will come with that. It is up to us to prove ourselves right and make sure we embrace it without losing who we are.”

Promotion triggers the £20m signing of the Manchester City ­loanee ­Taylor Harwood-Bellis on a permanent basis. Harwood-Bellis, who ­captained ­England Under-21s to European Championship victory last summer, missed just one league match after arriving on loan last ­September. He was one of four ­players in their starting lineup ­borrowed from top-flight clubs, with Flynn Downes from West Ham, David Brooks from Bournemouth and Ryan Fraser from Newcastle.

Brooks was replaced in the first half by Samuel Edozie after being forced off with a dislocated shoulder. “Hopefully a bit of champagne and a few beers will numb the pain,” ­Martin said. “Taylor becomes our player now, which is really nice. I don’t know how much we paid for him but ­whatever we paid it is worth it. One of the reasons I was so desperate to win was to continue working with him. I hope we can keep as many of that group together as we possibly can.”

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Daniel Farke, the Leeds manager, said while his players must use the pain of defeat to fuel their promotion push next season he warned it will be tough to beat their tally of 90 points in the regular season. Leeds finished third, six points behind second-placed Ipswich and seven behind the champions, Leicester.

“It will be difficult to come back stronger because overall 90 points is a great achievement,” said Farke, reiterating he plans to stay at the club. “We have to look at the bigger picture, 90 minutes, the way we played the playoffs, the way we played the final. There is no reason to dwell on it. We have to take this experience as extra motivation for us. The fans deserve a day to celebrate.

“We feel the pain and we are deeply disappointed we are not able to send our supporters home with something to cheer about and that we are not back in the promised land.”