Chelsea forward Oscar has signed a new contract which will keep him at the club until 2019, the Barclays Premier League club have announced.
Oscar has signed a new five-year deal with Chelsea, the Barclays Premier League leaders have confirmed.
The 23-year-old joined the club from Internacional in the summer of 2012 and has been a vital member of the first-team since, scoring 11 goals last season.
The attacking midfielder has added four more goals in 15 appearances this term and has now committed his future to Stamford Bridge until 2019.
"I am so happy because I love playing for Chelsea and living in England," he told the club's official website.
"I have enjoyed playing here for two years, and now I have five more, so I am very happy."
Since Mourinho's return to west London last summer Oscar has been earmarked for a pivotal role, with the Portuguese's insistence that he play the number 10 role seen as a large factor in Juan Mata's exit to Manchester United.
But Oscar has repaid his manager's faith, and that of Roberto Di Matteo who signed him, with a total of 27 goals in 126 Blues appearances.
Oscar began his career in his homeland with Sao Paulo but soon moved to Internacional where he spent two years before moving to the Blues for a fee of just under £20million.
He scored twice on his first start for the club in Champions League and helped the team to win the Europa League in 2013.
Oscar has also amassed 40 caps for Brazil since making his debut against Argentina in 2011 and has scored 11 times, including the only goal in the 7-1 humbling by Germany in last summer's World Cup semi-final.
Meanwhile, Chelsea defender Cesar Azpilicueta believes improved mental strength within the squad has made as much of a difference as their summer signings.
While striker Diego Costa's 10 goals in 11 league matches, having added to his total with the winner in Saturday's 2-1 victory at Liverpool, and Cesc Fabregas' creativity in midfield have given Jose Mourinho's side undoubted quality there has been a shift up in terms of character.
Mourinho pointed to as much when he praised his team for the ambition they showed at Anfield, especially in the second half having come back from an early Emre Can goal to equalise through Gary Cahill.
The Portuguese claimed most sides would have been happy to take a draw at Anfield but his team were not as Azpilicueta, back in the starting line-up after suspension, agreed.
"I think we are stronger mentally now. The players who came have given us another dimension as well," he said.
"I think you saw that. When the team was losing we were still really strong mentally.
"The whole squad know we have to fight together. Some players have more talent, some score goals, and sometimes we have to defend for them - but the main thing is we do it all as a team.
"We got it back to 1-1 pretty soon and after that did very well. Obviously we'd prefer not to go behind but that is going to happen at times.
"Over the last few games maybe we haven't played our best football and the scores have been tight but over the whole season you know that everyone can't keep playing very well and winning easy.
"We knew it would be tough here (at Anfield) but we fought so hard until the end - the aim was just to get those three points and we did.
"Last year we were so close to winning the title and this year we know it will be tough but that's what we want.
"We will see in May. We're on top of the table but that's a long way off, but we want as few problems as possible up to then."
The impact of Costa, who Mourinho believes is now over his injury problems, cannot be underestimated so far this season and he gives his team-mates the confidence they will always score.
"We're lucky to have three really good strikers. We showed it when he was out, when Didier (Drogba) and Loic (Remy) came in and were scoring," added the Spain international.
"Now he's back and scoring. He plays with high passion, he's always fighting for team, and is even after goals in training - he's a great finisher.
"If we analyse him he scores but helps so much in the team. Even in last five or 10 minutes he was pressing high and doing his job. That's great for the whole team."