Fans back in Brazil used to call him Bugs Bunny, apparently because of his lithe build. Chelsea fans just used to call him a donkey. But the player who was rashly derided as a waste of £18m just a few games into the season is now the darling of Stamford Bridge. Ramires's sumptuous chipped goal against Barcelona in the Camp Nou on Wednesday transformed the course of the Champions League semi-final and confirmed that initial perceptions of this atypical midfielder were wrong.

It was not the first time the 25-year-old had showed such finesse – 10 days earlier he scored in the FA Cup semi-final with a dainty dink over Tottenham's Carlo Cudicini – but there is a sense that doing it in the Camp Nou, at the end of a searing run from his own half and just after Barcelona seemed to have killed off the challenge of 10-men Chelsea, proved definitively that Ramires is a world-class player who belongs among the best. The grandeur of this goal made it a coming-of-age moment for the player.

"It was an amazing goal," says his team-mate Branislav Ivanovic, who started the move by winning possession before Ramires galloped forward from his own half to collect Frank Lampard's pass and lift the ball first time over the confounded Victor Valdes. "After such a long run it is very difficult to sustain your concentration and do what he did," says Ivanovic. "But he's Brazilian so I think it's natural for him."

At the start of the season the heckle from many in the Stamford Bridge crowd was precisely that Ramires did not seem Brazilian at all. He was about as far as it was possible to get from the stereotype of the samba magician, offering no flair or slight of foot. Carlo Ancelotti, it seemed, had splurged millions on a player who put the "jog" into O Jogo Bonito. The scrawny midfielder did not even show the toughness that all great Brazilian players possess, being shunted off the ball easily in his first few Premier League encounters after his arrival from Benfica. Great, thought the rash: a water carrier who keeps dropping the bucket.

"When he came here it was very difficult for him as everything changed [from the Portuguese league]", says Ivanovic. "But in the last couple of months he has played his best football. And from training with him I think he can go on to play twice as well as he is doing now – he is really a great player."

Roberto Di Matteo agrees. "He is an exceptional player for us," says the Chelsea interim manager. "He has so many qualities – one is his personality: he is a very humble man, a real team player."

As he has become more comfortable in this Chelsea team, it has become more reliant on him. With Michael Essien yet to recover his powers of yore, no one else offers the midfield drive and explosiveness that Ramires provides. Of the eight Premier League games Ramires has missed, Chelsea have won one – and that was against Wigan thanks to a goal that should have been ruled out for offside. John Terry receives the most attention, but of the four Chelsea players who will miss the Champions League final through suspension, Ramires will be the hardest to replace.

The booking that rules Ramires out of the final was for berating the referee after Andrés Iniesta scored Barcelona's second goal. "I was annoyed, I mentioned Terry's sending-off, he did not accept my complaints," explained Ramires. While it is admirable that he was then able to shelve his frustration to score his delicious goal two minutes later, it is also true that a propensity to incur needless bookings is the one obvious negative aspect to Ramires's play. The Champions League final on 19 May is the second major match he has missed through suspension – the former Brazil manager Dunga insists that they would not have lost to Holland in the 2010 World Cup quarter-final had Ramires not been banned.

Dunga is among Ramires's greatest admirers. In Brazil there is mounting dismay that his successor, Mano Menezes, does not share his appreciation. Menezes has omitted Ramires from all of this year's squads and has not included him among the many overage players on his 52-man preliminary list announced this week for the Olympics, which Brazil are determined to win. His Chelsea team-mate David Luiz is on the list, as are several midfielders whose club performances have been nowhere near as impressive as Ramires's this season. "I do not need to see Ramires, I know what he can do," Menezes said after Ramires's display against Barcelona intensified demands for the manager to recall him.

But it is not clear that Menezes does know what Ramires can do: when he did pick him last year, he deployed him as a holding midfielder alongside Liverpool's Lucas Leiva, suggesting that he has a limited understanding of the player's qualities, seeing his dynamism but not his creativity. "He can run a lot but he also understands football very well and that makes his forward movements very dangerous," says Ivanovic. Cruzeiro, the Brazilian club who signed Ramires from second division Joinville in 2008, were quick to realise this, converting him from a right-back to an attacking midfielder early in his career and Benfica pursued that policy after buying him for around £5m in 2009.

Bayern Munich do not need to worry, but Chelsea's remaining opponents this season, starting with QPRon Sunday, can expect further demonstrations of Ramires's repertoire of skills.

• This article was amended on 10 May 2012. The original said that André Villas-Boas, it seemed, had splurged millions on Ramires and that Benfica bought him in 2010. These have both been corrected.