Chelsea have confirmed the signing of Willian on a five-year deal having been successful in their pursuit of a work permit for the Brazil forward.

"I'm very happy to be here, it's been a dream of mine to come and play here," said the 25-year-old, who will wear the No22 shirt. "Chelsea are one of the best clubs in the world, and now I'm going to play for one of the best managers in the world, so I'm very happy and looking forward to it."

The London club struck a £32m agreement with the ailing Anzhi Makhachkala last week for the 25-year-old, trumping Tottenham Hotspur in the process despite the player having undergone a medical with Spurs last Thursday. The Chelsea owner, Roman Abramovich, made a personal call to his fellow Russian oligarch, Suleyman Kerimov, the Anzhi owner, to smooth the deal, albeit for a slightly higher price than that previously agreed with Tottenham.

While that prompted a furious reaction at White Hart Lane, Chelsea busied themselves preparing a case for Willian to be granted a permit under the "exceptional talent" clause as he is not a regular with Brazil. The manager, José Mourinho, supplied evidence on his behalf at the hearing on Wednesday with the panel duly convinced there is merit in the forward plying his trade in the Premier League.

Willian began his career in his homeland with Corinthians before moving to Europe with Shakhtar Donetsk in 2007. He made over 100 appearances for the Ukrainians and attracted interest from English clubs, before transferring to Anzhi in January. However, Kerimov has since withdrawn his previously lavish funding from the Dagestan club, which has prompted a fire-sale of their best talent over the summer.

Another Anzhi player, Samuel Eto'o, remains in talks with Chelsea over a potential one-year contract at Stamford Bridge to be reunited with Mourinho, with whom he won the European Cup while at Internazionale in 2010. The veteran Cameroon international is expected to waive the chance of a return to San Siro by moving to London on a short-term deal, with Chelsea now resigned to missing out on their principal summer target, Manchester United's Wayne Rooney.

The London club have reiterated that Juan Mata is not for sale despite Arsène Wenger suggesting on Tuesday that the playmaker was "on the market". The Spaniard, who is still working on gaining match fitness under Mourinho following a pre-season that started late after the Confederations Cup, has played a bit-part role under the Portuguese to date and his father and agent, Juan sr, was a guest in the Emirates Stadium directors' box at Tuesday's Champions League qualifier against Fenerbahce.

Wenger had almost signed Mata two years ago only for the Spaniard to join Chelsea. "I have heard like you, because I watched the game last night [between Manchester United and Chelsea] that Juan Mata could be on the market," said the Arsenal manager in the aftermath of his side's 2-0 success over the Turks. "I don't know ... there is anyway a reluctance in England to sell to each other. I like him."

But, while Mata has yet to make his mark under Mourinho, the Chelsea manager will not part with a midfielder who claimed the club's player of the year award in each of his two full seasons at the club, and any interest expressed in the 25-year-old ahead of Monday's transfer deadline will be knocked back.

Tottenham Hotspur had also hoped to prise Mata from Stamford Bridge, though their manager Andre Villas-Boas — who was in charge at Chelsea when the Spaniard was signed in 2011 — has admitted any enquiry would have been given short shrift by their London rivals.

"First, Chelsea wouldn't sell to Tottenham in any way or form, as they think that we are title contenders," said the Portuguese, whose side are yet to drop a point in the Premier League this season. "Mata is a great, great player – player of the season last season – very, very important player for Chelsea. They're just not going to strengthen another team that, in their opinion, are rivals for the title."