Leicester City delivered a new entry into their list of unlikely success stories with a stunning victory over Sevilla at the King Power Stadium that takes them into the Champions League quarter-finals.

The club and team that makes a habit of turning logic on its head did it again as high-flying La Liga side's 2-1 advantage from the first leg was overturned amid an atmosphere of passion and emotion that evoked memories of last season's Premier League title win.

It was made all the more remarkable by the fact that three weeks ago, after that first game in Spain, Leicester sacked Claudio Ranieri, the man who masterminded that title triumph, amid tales of dressing-room discontent and fears of relegation.

How have they undertaken this transformation? And how far can they now go in the Champions League?

From dreading the Championship to dreaming of Champions League glory

When Leicester sacked Ranieri on 23 February, the Champions League was an afterthought set alongside fears the Foxes were on course to drop into the Championship.

They had dredged a creditable 2-1 loss out of a performance that was the final curtain for the popular Italian - but it was wider concerns that led to his dismissal.

The club's Thai owners needed someone to rediscover the element that had been lost in the nine months since Leicester lifted the Premier League trophy in one of the greatest sporting stories ever told. They needed someone to keep them up, with any success in the Champions League falling into the category of added bonus.

They turned to Craig Shakespeare, who came to the club with Nigel Pearson and stayed on to ride shotgun to Ranieri in that dream season.

And, in an instant, the dial has been turned back. Shakespeare has restored this Leicester team to default, title-winning settings - and the transformation has been remarkable

Shakespeare, in charge until the end of the season, has won three out of three. Impressive wins against Liverpool and Hull have soothed relegation fears but this win over Sevilla is the most compelling vindication of his methods. It was the kind of victory on which reputations are made and, in the case of Leicester's players, revived.

He effectively restored the title team, with the obvious exception of Wilfred Ndidi for the departed N'Golo Kante, and ordered them to play in the same intense, counter-attacking manner - using the pace of Jamie Vardy and the creativity of Riyad Mahrez - that brought that success.

It was a move that now has self-belief sweeping through the club, players and supporters, like a tidal wave. To watch the Foxes hurry Sevilla out of their stride was the equivalent of being transported back to last season.

Shakespeare has gone back to improve the future. Leicester have returned to the uncomplicated success of last season, banishing the mediocrity and lacklustre performances of the early months of a season that threatened to be the biggest anti-climax of all.

When they lost 2-0 at relegation rivals Swansea on 12 February, a result that helped to seal Ranieri's fate, they were in 17th place with 21 points from 25 Premier League games. This was a club in freefall

Shakespeare's approach has been simple but very specific. Leicester have returned to what they do best and what opponents dislike most.

And in doing so, the King Power Stadium is back to the imposing arena it was last term.

Tuesday's win was driven by passion, noise and raw emotion. When the board went up to signal four minutes of stoppage time, a huge roar rippled around the stadium - a roar of inspiration, not fear.

Those closing stages were pure theatre as the clock ticked down in an electric atmosphere. All the ingredients that made Leicester such a success story last year were back.

There was still plenty of criticism of the club's players on social media on Tuesday from those who believed they downed tools under Ranieri only to pick them up once he was gone, but no-one seemed to care inside a thunderous King Power Stadium.

This beating of Sevilla was the most emphatic justification of the events of the past few weeks.

Ruthless, but right?

Leicester's Thai owners were painted as heartless, ruthless and almost the enemies of decency and manners when the dignified Ranieri was shown off the premises nine months after bringing them riches they could only have dreamed of.

It was significant that when Leicester made their post-Ranieri return with a 3-1 win at home to Liverpool on 27 February, there was a march of thanks to the departed manager and many banners of appreciation, but little acrimony or open criticism of the club's hierarchy.

This may have been a signal suggesting that, while their fans may have found the decision to remove the Italian uncomfortable, particularly given his obvious warmth and decency, they had been watching a floundering team and realised emergency action was needed.

The club's decision-makers made the move with a heavy heart but without sentiment. Relegation was the fear and it needed to be avoided - and it is unlikely supporters would have thanked them for being sentimental all the way into the Championship.

They have not looked for vindication or justification - remaining silent for the most part - but the performance against Sevilla and the securing of a place in the last eight of the Champions League is evidence that, no matter how unpalatable their sacking of Ranieri may have been to some, it was the right move.

Match of the Day presenter Gary Lineker, a former Leicester and England striker, tweeted that the decision was "inexplicable, unforgiveable and gut-wrenchingly sad". And there were many who shared his view.

Results since, and the celebrations at the final whistle on Tuesday after another moment of Foxes history, give further credence to what many regarded as a cruel move.

The Foxes' owners have a track record of taking the right decisions - and they look to have done so again.

They kept faith with former manager Nigel Pearson through a period of struggle and he mounted an unlikely survival campaign to stay in the Premier League. And when he was sacked, the appointment of Ranieri - greeted with widespread scepticism - was a masterstroke.

Former England defender Danny Mills, watching as a BBC Radio 5 live analyst on Tuesday, offered his support to the club's owners as he said: "It's just a different Leicester from what we have seen this season.

"All those fans who thought it was a disgrace that Ranieri was sacked have got to eat some humble pie."

It still would have tasted sweet to those who questioned that decision as they made their way out into the streets around the stadium amid scenes of wild celebration.

How far could they go?

It is surely stretching the credibility of even Leicester's scriptwriters to suggest they can win the Champions League - but who is to say they cannot make even more waves after Sevilla, Europa League winners three seasons in succession and third in La Liga, were beaten?

This was a fully deserved win against a side rated as potential dark horses in the competition and comes on the heels of an impressive dismissal of Liverpool.

The Foxes will be rank outsiders against Barcelona, Real Madrid, Bayern Munich, Borussia Dortmund, Juventus - or anyone who is pitted against them in the last eight.

However, they will not shy away from any challenge, especially not at home and especially not if this arena is the stage for the second leg.

There was a real air of intimidation, noise and theatre in the stadium against Sevilla and Leicester's fans are starting to dream again after the dark months between August and February.

Under Shakespeare, they are playing in a manner designed to unsettle any side who takes the measured approach - and they will do it backed by a 90-minute wall of sound.

All the odds suggest this latest great adventure should end at the next stage - but since when did the odds or logic come into this club's calculations?